The influence of the selection of macronutrients coupled with dietary energy density on the performance of broiler chickens

PubMed Central

Chrystal, Peter V.; Cowieson, Aaron J.; Truong, Ha H.; Moss, Amy F.; Selle, Peter H.

2017-01-01

A total of 360 male Ross 308 broiler chickens were used in a feeding study to assess the influence of macronutrients and energy density on feed intakes from 10 to 31 days post-hatch. The study comprised ten dietary treatments from five dietary combinations and two feeding approaches: sequential and choice feeding. The study included eight experimental diets and each dietary combination was made from three experimental diets. Choice fed birds selected between three diets in separate feed trays at the same time; whereas the three diets were offered to sequentially fed birds on an alternate basis during the experimental period. There were no differences between starch and protein intakes between choice and sequentially fed birds (P > 0.05) when broiler chickens selected between diets with different starch, protein and lipid concentrations. When broiler chickens selected between diets with different starch and protein but similar lipid concentrations, both sequentially and choice fed birds selected similar ratios of starch and protein intake (P > 0.05). However, when broiler chickens selected from diets with different protein and lipid but similar starch concentrations, choice fed birds had higher lipid intake (129 versus 118 g/bird, P = 0.027) and selected diets with lower protein concentrations (258 versus 281 g/kg, P = 0.042) than birds offered sequential diet options. Choice fed birds had greater intakes of the high energy diet (1471 g/bird, P < 0.0001) than low energy (197 g/bird) or medium energy diets (663 g/bird) whilst broiler chickens were offered diets with different energy densities but high crude protein (300 g/kg) or digestible lysine (17.5 g/kg) concentrations. Choice fed birds had lower FCR (1.217 versus 1.327 g/g, P < 0.0001) and higher carcass yield (88.1 versus 87.3%, P = 0.012) than sequentially fed birds. This suggests that the dietary balance between protein and energy is essential for optimal feed conversion efficiency. The intake path of macronutrients from 10–31 days in choice and sequential feeding groups were plotted and compared with the null path if broiler chickens selected equal amounts of the three diets in the combination. Regardless of feeding regimen, the intake paths of starch and protein are very close to the null path; however, lipid and protein intake paths in choice fed birds are father from the null path than sequentially fed birds. PMID:29053729

Selective wetting-induced micro-electrode patterning for flexible micro-supercapacitors.

PubMed

Kim, Sung-Kon; Koo, Hyung-Jun; Lee, Aeri; Braun, Paul V

2014-08-13

Selective wetting-induced micro-electrode patterning is used to fabricate flexible micro-supercapacitors (mSCs). The resulting mSCs exhibit high performance, mechanical stability, stable cycle life, and hold great promise for facile integration into flexible devices requiring on-chip energy storage. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Macro- and microscale investigation of selenium speciation in Blackfoot river, Idaho sediments.

PubMed

Oram, Libbie L; Strawn, Daniel G; Marcus, Matthew A; Fakra, Sirine C; Möller, Gregory

2008-09-15

The transport and bioavailability of selenium in the environment is controlled by its chemical speciation. However, knowledge of the biogeochemistry and speciation of Se in streambed sediment is limited. We investigated the speciation of Se in sediment cores from the Blackfoot River (BFR), Idaho using sequential extractions and synchrotron-based micro-X-ray fluorescence (micro-SXRF). We collected micro-SXRF oxidation state maps of Se in sediments, which had not been done on natural sediment samples. Selective extractions showed that most Se in the sediments is present as either (1) nonextractable Se or (2) base extractable Se. Results from micro-SXRF showed three defined species of Se were present in all four samples: Se(-II,O), Se(IV), and Se(VI). Se(-II,O) was the predominant species in samples from one location, and Se(IV) was the predominant species in samples from a second location. Results from both techniques were consistent, and suggested that the predominant species were Se(-II) species associated with recalcitrant organic matter, and Se(IV) species tightly bound to organic materials. This information can be used to predict the biogeochemical cycling and bioavailability of Se in streambed sediment environments.

Application of Sequential Extractions and X-ray Absorption Spectroscopy to Determine the Speciation of Chromium in Northern New Jersey Marsh Soils Developed in Chromite ore Processing Residue (COPR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elzinga, E.; Cirmo, A

2010-01-01

The Cr speciation in marsh soils developed in weathering chromite ore processing residue (COPR) was characterized using sequential extractions and synchrotron microbeam and bulk X-ray absorption spectroscopic (XAS) analyses. The sequential extractions suggested substantial Cr associated with reducible and oxidizable soil components, and significant non-extractable residual Cr. Notable differences in Cr speciation estimates from three extraction schemes underscore the operationally defined nature of Cr speciation provided by these methods. Micro X-ray fluorescence maps and {mu}-XAS data indicated the presence of {micro}m-sized chromite particles scattered throughout the weathered COPR matrix. These particles derive from the original COPR material, and have relativelymore » high resistance towards weathering, and therefore persist even after prolonged leaching. Bulk XAS data further indicated Cr(III) incorporated in Fe(OH){sub 3}, and Cr(III) associated with organic matter. The low Cr contents of the weathered material (200-850 ppm) compared to unweathered COPR (20,000-60,000 ppm) point to substantial Cr leaching during COPR weathering, with partial repartitioning of released Cr into secondary Fe(OH){sub 3} phases and organics. The effects of anoxia on Cr speciation, and the potential of active COPR weathering releasing Cr(VI) deeper in the profile require further study.« less

Sparse generalized linear model with L0 approximation for feature selection and prediction with big omics data.

PubMed

Liu, Zhenqiu; Sun, Fengzhu; McGovern, Dermot P

2017-01-01

Feature selection and prediction are the most important tasks for big data mining. The common strategies for feature selection in big data mining are L 1 , SCAD and MC+. However, none of the existing algorithms optimizes L 0 , which penalizes the number of nonzero features directly. In this paper, we develop a novel sparse generalized linear model (GLM) with L 0 approximation for feature selection and prediction with big omics data. The proposed approach approximate the L 0 optimization directly. Even though the original L 0 problem is non-convex, the problem is approximated by sequential convex optimizations with the proposed algorithm. The proposed method is easy to implement with only several lines of code. Novel adaptive ridge algorithms ( L 0 ADRIDGE) for L 0 penalized GLM with ultra high dimensional big data are developed. The proposed approach outperforms the other cutting edge regularization methods including SCAD and MC+ in simulations. When it is applied to integrated analysis of mRNA, microRNA, and methylation data from TCGA ovarian cancer, multilevel gene signatures associated with suboptimal debulking are identified simultaneously. The biological significance and potential clinical importance of those genes are further explored. The developed Software L 0 ADRIDGE in MATLAB is available at https://github.com/liuzqx/L0adridge.

Micro-evolutionary implications of allozymic and morphometric variations in sealworms Pseudoterranova sp. (Ascaridoidea: Anisakidae) among sympatric hosts from the southeastern Pacific Ocean.

PubMed

George-Nascimento, M; Llanos, A

1995-10-01

We found significant morphometric and electrophoretic differences between sealworm larvae collected from four sympatric fish host species off the central coast of Chile. The South American sea lion, Otaria byronia, is a suitable host and most likely the only definitive host species in the study area. Morphological patterns of caudal papillae in adult males collected from sea lions and electrophoretic evidence from larvae and adults substantiate our conclusion that they belong to just one, new species yet to be described. The genetic and morphometric differences found between sealworm larvae from sympatric fish hosts may be due to selective pressures arising from the internal environment of the intermediate hosts, although they may serve only for passing sequential filters along the life cycle. The discussion deals with the roles that definitive and intermediate hosts may play in the micro-evolutionary processes of sealworms.

Controllable Si (100) micro/nanostructures by chemical-etching-assisted femtosecond laser single-pulse irradiation

NASA Astrophysics Data System (ADS)

Li, Xiaowei; Xie, Qian; Jiang, Lan; Han, Weina; Wang, Qingsong; Wang, Andong; Hu, Jie; Lu, Yongfeng

2017-05-01

In this study, silicon micro/nanostructures of controlled size and shape are fabricated by chemical-etching-assisted femtosecond laser single-pulse irradiation, which is a flexible, high-throughput method. The pulse fluence is altered to create various laser printing patterns for the etching mask, resulting in the sequential evolution of three distinct surface micro/nanostructures, namely, ring-like microstructures, flat-top pillar microstructures, and spike nanostructures. The characterized diameter of micro/nanostructures reveals that they can be flexibly tuned from the micrometer (˜2 μm) to nanometer (˜313 nm) scales by varying the laser pulse fluence in a wide range. Micro-Raman spectroscopy and transmission electron microscopy are utilized to demonstrate that the phase state changes from single-crystalline silicon (c-Si) to amorphous silicon (a-Si) after single-pulse femtosecond laser irradiation. This amorphous layer with a lower etching rate then acts as a mask in the wet etching process. Meanwhile, the on-the-fly punching technique enables the efficient fabrication of large-area patterned surfaces on the centimeter scale. This study presents a highly efficient method of controllably manufacturing silicon micro/nanostructures with different single-pulse patterns, which has promising applications in the photonic, solar cell, and sensors fields.

A non-symmetric pillar[5]arene based on triazole-linked 8-oxyquinolines as a sequential sensor for thorium(IV) followed by fluoride ions.

PubMed

Fang, Yuyu; Li, Caixia; Wu, Lei; Bai, Bing; Li, Xing; Jia, Yiming; Feng, Wen; Yuan, Lihua

2015-09-07

A novel non-symmetric pillar[5]arene bearing triazole-linked 8-oxyquinolines at one rim was synthesized and demonstrated as a sequential fluorescence sensor for thorium(iv) followed by fluoride ions with high sensitivity and selectivity.

REML/BLUP and sequential path analysis in estimating genotypic values and interrelationships among simple maize grain yield-related traits.

PubMed

Olivoto, T; Nardino, M; Carvalho, I R; Follmann, D N; Ferrari, M; Szareski, V J; de Pelegrin, A J; de Souza, V Q

2017-03-22

Methodologies using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) in combination with sequential path analysis in maize are still limited in the literature. Therefore, the aims of this study were: i) to use REML/BLUP-based procedures in order to estimate variance components, genetic parameters, and genotypic values of simple maize hybrids, and ii) to fit stepwise regressions considering genotypic values to form a path diagram with multi-order predictors and minimum multicollinearity that explains the relationships of cause and effect among grain yield-related traits. Fifteen commercial simple maize hybrids were evaluated in multi-environment trials in a randomized complete block design with four replications. The environmental variance (78.80%) and genotype-vs-environment variance (20.83%) accounted for more than 99% of the phenotypic variance of grain yield, which difficult the direct selection of breeders for this trait. The sequential path analysis model allowed the selection of traits with high explanatory power and minimum multicollinearity, resulting in models with elevated fit (R 2 > 0.9 and ε < 0.3). The number of kernels per ear (NKE) and thousand-kernel weight (TKW) are the traits with the largest direct effects on grain yield (r = 0.66 and 0.73, respectively). The high accuracy of selection (0.86 and 0.89) associated with the high heritability of the average (0.732 and 0.794) for NKE and TKW, respectively, indicated good reliability and prospects of success in the indirect selection of hybrids with high-yield potential through these traits. The negative direct effect of NKE on TKW (r = -0.856), however, must be considered. The joint use of mixed models and sequential path analysis is effective in the evaluation of maize-breeding trials.

High-Performance Substrates for SERS Detection via Microphotonic Photopolymer Characterization and Coating With Functionalized Hydrogels

DTIC Science & Technology

2006-11-26

with controlled micro and nanostructure for highly selective, high sensitivity assays. The process was modeled and a procedure for fabricating SERS...small volumes with controlled micro and nanostructure for highly selective, high sensitivity assays. We proved the feasibility of the technique and...films templated by colloidal crystals. The control over the film structure allowed optimizing their performance for potential sensor applications. The

Microfabricated thermal modulator for comprehensive two-dimensional micro gas chromatography: design, thermal modeling, and preliminary testing.

PubMed

Kim, Sung-Jin; Reidy, Shaelah M; Block, Bruce P; Wise, Kensall D; Zellers, Edward T; Kurabayashi, Katsuo

2010-07-07

In comprehensive two-dimensional gas chromatography (GC x GC), a modulator is placed at the juncture between two separation columns to focus and re-inject eluting mixture components, thereby enhancing the resolution and the selectivity of analytes. As part of an effort to develop a microGC x microGC prototype, in this report we present the design, fabrication, thermal operation, and initial testing of a two-stage microscale thermal modulator (microTM). The microTM contains two sequential serpentine Pyrex-on-Si microchannels (stages) that cryogenically trap analytes eluting from the first-dimension column and thermally inject them into the second-dimension column in a rapid, programmable manner. For each modulation cycle (typically 5 s for cooling with refrigeration work of 200 J and 100 ms for heating at 10 W), the microTM is kept approximately at -50 degrees C by a solid-state thermoelectric cooling unit placed within a few tens of micrometres of the device, and heated to 250 degrees C at 2800 degrees C s(-1) by integrated resistive microheaters and then cooled back to -50 degrees C at 250 degrees C s(-1). Thermal crosstalk between the two stages is less than 9%. A lumped heat transfer model is used to analyze the device design with respect to the rates of heating and cooling, power dissipation, and inter-stage thermal crosstalk as a function of Pyrex-membrane thickness, air-gap depth, and stage separation distance. Experimental results are in agreement with trends predicted by the model. Preliminary tests using a conventional capillary column interfaced to the microTM demonstrate the capability for enhanced sensitivity and resolution as well as the modulation of a mixture of alkanes.

A rapid method for the sequential separation of polonium, plutonium, americium and uranium in drinking water.

PubMed

Lemons, B; Khaing, H; Ward, A; Thakur, P

2018-06-01

A new sequential separation method for the determination of polonium and actinides (Pu, Am and U) in drinking water samples has been developed that can be used for emergency response or routine water analyses. For the first time, the application of TEVA chromatography column in the sequential separation of polonium and plutonium has been studied. This method utilizes a rapid Fe +3 co-precipitation step to remove matrix interferences, followed by plutonium oxidation state adjustment to Pu 4+ and an incubation period of ~ 1 h at 50-60 °C to allow Po 2+ to oxidize to Po 4+ . The polonium and plutonium were then separated on a TEVA column, while separation of americium from uranium was performed on a TRU column. After separation, polonium was micro-precipitated with copper sulfide (CuS), while actinides were micro co-precipitated using neodymium fluoride (NdF 3 ) for counting by the alpha spectrometry. The method is simple, robust and can be performed quickly with excellent removal of interferences, high chemical recovery and very good alpha peak resolution. The efficiency and reliability of the procedures were tested by using spiked samples. The effect of several transition metals (Cu 2+ , Pb 2+ , Fe 3+ , Fe 2+ , and Ni 2+ ) on the performance of this method were also assessed to evaluate the potential matrix effects. Studies indicate that presence of up to 25 mg of these cations in the samples had no adverse effect on the recovery or the resolution of polonium alpha peaks. Copyright © 2018 Elsevier Ltd. All rights reserved.

Two-column sequential injection chromatography--new approach for fast and effective analysis and its comparison with gradient elution chromatography.

PubMed

Chocholous, Petr; Satínský, Dalibor; Sklenárová, Hana; Solich, Petr

2010-05-23

This work presents novel approach in low-pressure chromatography flow systems--two-column Sequential Injection Chromatography (2-C SIC) and its comparison with gradient elution chromatography on the same instrument. The system was equipped with two different chromatographic columns (connected to selection valve in parallel design) for isocratic separation and determination of all components in composed anti-inflammatory pharmaceutical preparation (tablets). The sample was first injected on the first column of length 30 mm where less retained analytes were separated and then the sample was injected on the second column of length 10 mm where more retained analytes were separated. The SIC system was based on a commercial SIChrom manifold (8-port high-pressure selection valve and medium-pressure syringe pump with 4 mL reservoir) (FIAlab, USA) with two commercially available monolithic columns the "first column" Chromolith Flash RP-18e (25 mm x 4.6 mm i.d. with guard column 5 mm x 4.6 mm i.d.) and the "second column" Chromolith RP-18e (10 mm x 4.6 mm i.d.) and CCD UV-vis detector USB 4000 with micro-volume 1.0 cm Z flow cell. Two mobile phases were used for analysis (one for each column). The mobile phase 1 used for elution of paracetamol, caffeine and salicylic acid (internal standard) was acetonitrile/water (10:90, v/v, the water part of pH 3.5 adjusted with acetic acid), flow rate was 0.9 mL min(-1) (volume 3.0 mL of mobile phase per analysis). The mobile phase 2 used for elution of propyphenazone was acetonitrile/water (30:70, v/v); flow rate was 1.2 mL min(-1) (volume 1.5 mL of mobile phase per analysis). Absorbance was monitored at 210 nm. Samples were prepared by dissolving of one tablet in 30% acetonitrile and 10 microL of filtered supernatant was injected on each column (2 x 10 microL). The chromatographic resolution between all compounds was >1.45 and analysis time was 5.5 min under the optimal conditions. Limits of detection were determined at 0.4 microg mL(-1) for paracetamol, at 0.5 microg mL(-1) for caffeine and at 0.7 microg mL(-1) for propyphenazone. The new two-column chromatographic set-up developed as an alternative approach to gradient elution chromatography shows evident advantages (time and solvent reduction more than one-third) as compared with single-column gradient SIC method with Chromolith Flash RP-18 (25 mm x 4.6 mm i.d. with guard column 5 mm x 4.6 mm i.d.). Copyright 2010 Elsevier B.V. All rights reserved.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents, selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1993-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Preparing the Teacher of Tomorrow

ERIC Educational Resources Information Center

Hemp, Paul E.

1976-01-01

Suggested ways of planning and conducting high quality teacher preparation programs are discussed under major headings of student selection, sequential courses and experiences, and program design. (HD)

Apatinib inhibits VEGFR-2 and angiogenesis in an in vivo murine model of nasopharyngeal carcinoma.

PubMed

Peng, Qiu-Xia; Han, Yun-Wei; Zhang, Yan-Ling; Hu, Jie; Fan, Juan; Fu, Shao-Zhi; Xu, Shan; Wan, Qiang

2017-08-08

Angiogenesis is initiated by the activation of the vascular epidermal growth factor receptor-2 (VEGFR-2) by the vascular epidermal growth factor (VEGF) ligand. Overexpression of VEGFR-2 increases the growth of nasopharyngeal carcinomas (NPC). Apatinib (YN968D1) is a highly-selective inhibitor of VEGFR-2, but its effects on NPC have not been hitherto investigated. In the present study, CNE-2 NPC cells were xenografted into 132 nude mice, which were treated with one of 6 drug regimens of apatinib administered alone or in combination with cisplatin (DDP). The impact of treatment regimens on the growth, microvascularization, apoptosis, and metabolic response of tumors, as well as mouse survival was determined by histopathology, immunohistochemistry (VEGFR-2 and CD31), terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL), micro 18F-FDG PET/CT imaging and survival curves. Administration of apatinib alone inhibited tumor growth, reduced microvascular density, and facilitated the apoptosis of tumors. Tumors treated simultaneously with apatinib and cisplatin exhibited significantly-increased inhibition of tumor growth, prolonged survival time, decreased expression of VEGFR-2, reduced microvascular density, and frequency of apoptosis over standalone and sequential administration therapy. Tumors treated simultaneously with apatinib and cisplatin had the lowest uptake of FDG. Taken together, the simultaneous administration of apatinib and cisplatin improves the therapeutic efficacy over standalone treatments, which also led to improved efficacy over sequential administration regimens. VEGFR-2 is an important predictive marker for efficacy of apatinib treatment of NPC.

Building a Lego wall: Sequential action selection.

PubMed

Arnold, Amy; Wing, Alan M; Rotshtein, Pia

2017-05-01

The present study draws together two distinct lines of enquiry into the selection and control of sequential action: motor sequence production and action selection in everyday tasks. Participants were asked to build 2 different Lego walls. The walls were designed to have hierarchical structures with shared and dissociated colors and spatial components. Participants built 1 wall at a time, under low and high load cognitive states. Selection times for correctly completed trials were measured using 3-dimensional motion tracking. The paradigm enabled precise measurement of the timing of actions, while using real objects to create an end product. The experiment demonstrated that action selection was slowed at decision boundary points, relative to boundaries where no between-wall decision was required. Decision points also affected selection time prior to the actual selection window. Dual-task conditions increased selection errors. Errors mostly occurred at boundaries between chunks and especially when these required decisions. The data support hierarchical control of sequenced behavior. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Applying discursive approaches to health psychology.

PubMed

Seymour-Smith, Sarah

2015-04-01

The aim of this paper is to outline the contribution of two strands of discursive research, glossed as 'macro' and 'micro,' to the field of health psychology. A further goal is to highlight some contemporary debates in methodology associated with the use of interview data versus more naturalistic data in qualitative health research. Discursive approaches provide a way of analyzing talk as a social practice that considers how descriptions are put together and what actions they achieve. A selection of recent examples of discursive research from one applied area of health psychology, studies of diet and obesity, are drawn upon in order to illustrate the specifics of both strands. 'Macro' discourse work in psychology incorporates a Foucauldian focus on the way that discourses regulate subjectivities, whereas the concept of interpretative repertoires affords more agency to the individual: both are useful for identifying the cultural context of talk. Both 'macro' and 'micro' strands focus on accountability to varying degrees. 'Micro' Discursive Psychology, however, pays closer attention to the sequential organization of constructions and focuses on naturalistic settings that allow for the inclusion of an analysis of the health professional. Diets are typically depicted as an individual responsibility in mainstream health psychology, but discursive research highlights how discourses are collectively produced and bound up with social practices. (c) 2015 APA, all rights reserved).

[Application of selection criteria in sequential double lung transplantation].

PubMed

Borro, J M; Tarazona, V; Vicente, R; Cafarena, J M; Ramos, F; Sales, G; Galán, G; Lozano, C; Morant, P; Calvo, V; Morcillo, A; París, F

1999-03-01

Since the first sequential double lung transplant was performed in 1986, such procedures have been increasing in number and the criteria used as indications for this type of surgery have broadened. Our aim was to reflect on the application of selection criteria and to describe the anesthetic and surgical techniques and postoperative follow-up of 72 patients who underwent this type of transplant surgery between March 1993 and December 1998. Actuarial survival five years after surgery was 74.4%. Among patients requiring transplantation after septic disease, actuarial survival was 90.8% for cystic fibrosis and 88.2% for bronchiectasis. Of the preoperative risk factors analyzed (prior surgery, pachypleuritis, multiresistant germs, poor nutrition, mechanical ventilation and corticoid therapy), only prior treatment with high doses of corticoids proved significant. Eleven patients have been diagnosed of bronchiolitis obliterans, four have died and only two continue to experience difficulties in daily living. The high survival rate and the restriction-free life after recovery lead us to consider sequential double lung transplantation to be the treatment of choice for all pulmonary diseases.

Atrocities and Confrontational Tension

PubMed Central

Klusemann, Stefan

2009-01-01

This paper presents an analysis of video-recordings and other micro-level data of the 1995 Srebrenica massacre in Bosnia-and-Herzegovina. It focuses on the sequential unfolding of micro-interactions and emotional dynamics before, and over the course of the atrocity. The paper argues that massacres have a pattern of situational emergence: local emotional dynamics are crucial to explain where and when atrocities do or do not come off and what form they take on the micro-level. It is shown that (1) micro-interactions constitute situational turning-points, towards or away from atrocities and that (2) local emotional dynamics shape the internal structure of atrocities, i.e. their internal dynamics of killings. The analysis is based on recent advances in the micro-sociology of violence by Collins, Katz, and Grossman, as well as Ekman's research tools for identifying emotional cues in micro-data. PMID:19936029

Preparation of wafer-level glass cavities by a low-cost chemical foaming process (CFP).

PubMed

Shang, Jintang; Chen, Boyin; Lin, Wei; Wong, Ching-Ping; Zhang, Di; Xu, Chao; Liu, Junwen; Huang, Qing-An

2011-04-21

A novel foaming process-chemical foaming process (CFP)-using foaming agents to fabricate wafer-level micro glass cavities including channels and bubbles was investigated. The process consists of the following steps sequentially: (1) shallow cavities were fabricated by a wet etching on a silicon wafer; (2) powders of a proper foaming agent were placed in a silicon cavity, named 'mother cavity', on the etched silicon surface; (3) the silicon cavities were sealed with a glass wafer by anodic bonding; (4) the bonded wafers were heated to above the softening point of the glass, and baked for several minutes, when the gas released by the decomposition of the foaming agent in the 'mother cavity' went into the other sealed interconnected silicon cavities to foam the softened glass into cylindrical channels named 'daughter channels', or spherical bubbles named 'son bubbles'. Results showed that wafer-level micro glass cavities with smooth wall surfaces were achieved successfully without contamination by the CFP. A model for the CFP was proposed to predict the final shape of the glass cavity. Experimental results corresponded with model predictions. The CFP provides a low-cost avenue to preparation of micro glass cavities of high quality for applications such as micro-reactors, micro total analysis systems (μTAS), analytical and bio-analytical applications, and MEMS packaging.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-10-25

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-04-05

A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents, selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 87 figures.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-10-25

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Organocatalytic asymmetric anti-selective Michael reactions of aldehydes and the sequential reduction/lactonization/Pauson-Khand reaction for the enantioselective synthesis of highly functionalized hydropentalenes.

PubMed

Hong, Bor-Cherng; Dange, Nitin S; Yen, Po-Jen; Lee, Gene-Hsiang; Liao, Ju-Hsiou

2012-10-19

A new method has been developed for the enantioselective synthesis of highly functionalized hydropentalenes bearing up to four stereogenic centers with high stereoselectivity (up to 99% ee). This process combines an enantioselective organocatalytic anti-selective Michael addition with a highly efficient one-pot reduction/lactonization/Pauson-Khand reaction sequence. The structures and absolute configurations of the products were confirmed by X-ray analysis.

The novel imidazopyridine 2-[2-(4-methoxy-pyridin-2-yl)-ethyl]-3H-imidazo[4,5-b]pyridine (BYK191023) is a highly selective inhibitor of the inducible nitric-oxide synthase.

PubMed

Strub, Andreas; Ulrich, Wolf-Rüdiger; Hesslinger, Christian; Eltze, Manfrid; Fuchss, Thomas; Strassner, Jochen; Strand, Susanne; Lehner, Martin D; Boer, Rainer

2006-01-01

We have identified imidazopyridine derivatives as a novel class of NO synthase inhibitors with high selectivity for the inducible isoform. 2-[2-(4-Methoxy-pyridin-2-yl)-ethyl]-3H-imidazo[4,5-b]pyridine (BYK191023) showed half-maximal inhibition of crudely purified human inducible (iNOS), neuronal (nNOS), and endothelial (eNOS) NO synthases at 86 nM, 17 microM, and 162 microM, respectively. Inhibition of inducible NO synthase was competitive with l-arginine, pointing to an interaction of BYK191023 with the catalytic center of the enzyme. In radioligand and surface plasmon resonance experiments, BYK191023 exhibited an affinity for iNOS, nNOS, and eNOS of 450 nM, 30 microM, and >500 microM, respectively. Inhibition of cellular nitrate/nitrite synthesis in RAW, rat mesangium, and human embryonic kidney 293 cells after iNOS induction showed 40- to 100-fold higher IC(50) values than at the isolated enzyme, in agreement with the much higher l-arginine concentrations in cell culture media and inside intact cells. BYK191023 did not show any toxicity in various rodent and human cell lines up to high micromolar concentrations. The inhibitory potency of BYK191023 was tested in isolated organ models of iNOS (lipopolysaccharide-treated and phenylephrine-precontracted rat aorta; IC(50) = 7 microM), eNOS (arecaidine propargyl ester-induced relaxation of phenylephrine-precontracted rat aorta; IC(50) > 100 microM), and nNOS (field-stimulated relaxation of phenylephrine-precontracted rabbit corpus cavernosum; IC(50) > 100 microM). These data confirm the high selectivity of BYK191023 for iNOS over eNOS and nNOS found at isolated enzymes. In summary, we have identified a new highly selective iNOS inhibitor structurally unrelated to known compounds and l-arginine. BYK191023 is a valuable tool for the investigation of iNOS-mediated effects in vitro and in vivo.

Using Bayesian Nonparametric Hidden Semi-Markov Models to Disentangle Affect Processes during Marital Interaction

PubMed Central

Griffin, William A.; Li, Xun

2016-01-01

Sequential affect dynamics generated during the interaction of intimate dyads, such as married couples, are associated with a cascade of effects—some good and some bad—on each partner, close family members, and other social contacts. Although the effects are well documented, the probabilistic structures associated with micro-social processes connected to the varied outcomes remain enigmatic. Using extant data we developed a method of classifying and subsequently generating couple dynamics using a Hierarchical Dirichlet Process Hidden semi-Markov Model (HDP-HSMM). Our findings indicate that several key aspects of existing models of marital interaction are inadequate: affect state emissions and their durations, along with the expected variability differences between distressed and nondistressed couples are present but highly nuanced; and most surprisingly, heterogeneity among highly satisfied couples necessitate that they be divided into subgroups. We review how this unsupervised learning technique generates plausible dyadic sequences that are sensitive to relationship quality and provide a natural mechanism for computational models of behavioral and affective micro-social processes. PMID:27187319

In-line micro-matrix solid-phase dispersion extraction for simultaneous separation and extraction of Sudan dyes in different spices.

PubMed

Rajabi, Maryam; Sabzalian, Sedigheh; Barfi, Behruz; Arghavani-Beydokhti, Somayeh; Asghari, Alireza

2015-12-18

A novel, simple, fast, and miniaturized method, termed in-line micro-matrix solid-phase dispersion (in-line MMSPD), coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous extraction and determination of Sudan dyes (i.e. Sudan I-IV, Sudan orange G, Sudan black B, and Sudan red G) with the aid of an experimental design strategy. In this method, a matrix solid-phase dispersion (MSPD) column including a suitable mixture of polar sorbents was inserted in the mobile phase pathway, and while the interfering compounds were retained, the analytes were eluted and entered into the analytical column. In this way, the extraction, elution, and separation of the analytes were performed sequentially. Under the optimal experimental conditions (including the amount of sample, 0.0426g; amount of dispersant phase, 0.0216g of florisil, 0.0227g of silica, 0.0141g of alumina; and blending time, 112s), the limits of detection (LODs), limits of quantification, linear dynamic ranges, and recoveries were obtained to be 0.3-15.3μgkg(-1), 1-50μgkg(-1), 50-28,000μgkg(-1), and 94.5-99.1%, respectively. The results obtained showed that determination of the selected Sudan dyes in food samples using an enough sensitive and a simple analytically validated method like in-line MMSPD may offer a suitable screening method, which could be useful for food analysis and adulteration. Copyright © 2015 Elsevier B.V. All rights reserved.

Fabrication of an infrared Shack-Hartmann sensor by combining high-speed single-point diamond milling and precision compression molding processes.

PubMed

Zhang, Lin; Zhou, Wenchen; Naples, Neil J; Yi, Allen Y

2018-05-01

A novel fabrication method by combining high-speed single-point diamond milling and precision compression molding processes for fabrication of discontinuous freeform microlens arrays was proposed. Compared with slow tool servo diamond broaching, high-speed single-point diamond milling was selected for its flexibility in the fabrication of true 3D optical surfaces with discontinuous features. The advantage of single-point diamond milling is that the surface features can be constructed sequentially by spacing the axes of a virtual spindle at arbitrary positions based on the combination of rotational and translational motions of both the high-speed spindle and linear slides. By employing this method, each micro-lenslet was regarded as a microstructure cell by passing the axis of the virtual spindle through the vertex of each cell. An optimization arithmetic based on minimum-area fabrication was introduced to the machining process to further increase the machining efficiency. After the mold insert was machined, it was employed to replicate the microlens array onto chalcogenide glass. In the ensuing optical measurement, the self-built Shack-Hartmann wavefront sensor was proven to be accurate in detecting an infrared wavefront by both experiments and numerical simulation. The combined results showed that precision compression molding of chalcogenide glasses could be an economic and precision optical fabrication technology for high-volume production of infrared optics.

Sequential ALK Inhibitors Can Select for Lorlatinib-Resistant Compound ALK Mutations in ALK-Positive Lung Cancer.

PubMed

Yoda, Satoshi; Lin, Jessica J; Lawrence, Michael S; Burke, Benjamin J; Friboulet, Luc; Langenbucher, Adam; Dardaei, Leila; Prutisto-Chang, Kylie; Dagogo-Jack, Ibiayi; Timofeevski, Sergei; Hubbeling, Harper; Gainor, Justin F; Ferris, Lorin A; Riley, Amanda K; Kattermann, Krystina E; Timonina, Daria; Heist, Rebecca S; Iafrate, A John; Benes, Cyril H; Lennerz, Jochen K; Mino-Kenudson, Mari; Engelman, Jeffrey A; Johnson, Ted W; Hata, Aaron N; Shaw, Alice T

2018-06-01

The cornerstone of treatment for advanced ALK-positive lung cancer is sequential therapy with increasingly potent and selective ALK inhibitors. The third-generation ALK inhibitor lorlatinib has demonstrated clinical activity in patients who failed previous ALK inhibitors. To define the spectrum of ALK mutations that confer lorlatinib resistance, we performed accelerated mutagenesis screening of Ba/F3 cells expressing EML4-ALK. Under comparable conditions, N -ethyl- N -nitrosourea (ENU) mutagenesis generated numerous crizotinib-resistant but no lorlatinib-resistant clones harboring single ALK mutations. In similar screens with EML4-ALK containing single ALK resistance mutations, numerous lorlatinib-resistant clones emerged harboring compound ALK mutations. To determine the clinical relevance of these mutations, we analyzed repeat biopsies from lorlatinib-resistant patients. Seven of 20 samples (35%) harbored compound ALK mutations, including two identified in the ENU screen. Whole-exome sequencing in three cases confirmed the stepwise accumulation of ALK mutations during sequential treatment. These results suggest that sequential ALK inhibitors can foster the emergence of compound ALK mutations, identification of which is critical to informing drug design and developing effective therapeutic strategies. Significance: Treatment with sequential first-, second-, and third-generation ALK inhibitors can select for compound ALK mutations that confer high-level resistance to ALK-targeted therapies. A more efficacious long-term strategy may be up-front treatment with a third-generation ALK inhibitor to prevent the emergence of on-target resistance. Cancer Discov; 8(6); 714-29. ©2018 AACR. This article is highlighted in the In This Issue feature, p. 663 . ©2018 American Association for Cancer Research.

Kinetic mechanism and quaternary structure of Aminobacter aminovorans NADH:flavin oxidoreductase: an unusual flavin reductase with bound flavin.

PubMed

Russell, Thomas R; Demeler, Borries; Tu, Shiao-Chun

2004-02-17

The homodimeric NADH:flavin oxidoreductase from Aminobacter aminovorans is an NADH-specific flavin reductase herein designated FRD(Aa). FRD(Aa) was characterized with respect to purification yields, thermal stability, isoelectric point, molar absorption coefficient, and effects of phosphate buffer strength and pH on activity. Evidence from this work favors the classification of FRD(Aa) as a flavin cofactor-utilizing class I flavin reductase. The isolated native FRD(Aa) contained about 0.5 bound riboflavin-5'-phosphate (FMN) per enzyme monomer, but one bound flavin cofactor per monomer was obtainable in the presence of excess FMN or riboflavin. In addition, FRD(Aa) holoenzyme also utilized FMN, riboflavin, or FAD as a substrate. Steady-state kinetic results of substrate titrations, dead-end inhibition by AMP and lumichrome, and product inhibition by NAD(+) indicated an ordered sequential mechanism with NADH as the first binding substrate and reduced FMN as the first leaving product. This is contrary to the ping-pong mechanism shown by other class I flavin reductases. The FMN bound to the native FRD(Aa) can be fully reduced by NADH and subsequently reoxidized by oxygen. No NADH binding was detected using 90 microM FRD(Aa) apoenzyme and 300 microM NADH. All results favor the interpretation that the bound FMN was a cofactor rather than a substrate. It is highly unusual that a flavin reductase using a sequential mechanism would require a flavin cofactor to facilitate redox exchange between NADH and a flavin substrate. FRD(Aa) exhibited a monomer-dimer equilibrium with a K(d) of 2.7 microM. Similarities and differences between FRD(Aa) and certain flavin reductases are discussed.

Design, fabrication and test of a pneumatically controlled, renewable, microfluidic bead trapping device for sequential injection analysis applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Guocheng; Lu, Donglai; Fu, Zhifeng

This paper describes the design, fabrication, and testing of a pneumatically controlled,renewable, microfluidic device for conducting bead-based assays in an automated sequential injection analysis system. The device used a “brick wall”-like pillar array (pillar size: 20 μm length X 50 μm width X 45 μm height) with 5 μm gaps between the pillars serving as the micro filter. The flow channel where bead trapping occurred is 500 μm wide X 75 μm deep. An elastomeric membrane and an air chamber were located underneath the flow channel. By applying pressure to the air chamber, the membrane is deformed and pushed upwardmore » against the filter structure. This effectively traps beads larger than 5 μm and creates a “bed” or micro column of beads that can be perfused and washed with liquid samples and reagents. Upon completion of the assay process, the pressure is released and the beads are flushed out from underneath the filter structure to renew the device. Mouse IgG was used as a model analyte to test the feasibility of using the proposed device for immunoassay applications. Resulting microbeads from an on-chip fluorescent immunoassay were individually examined using flow cytometry. The results show that the fluorescence signal intensity distribution is fairly narrow indicating high chemical reaction uniformity among the beads population. Electrochemical onchip assay was also conducted. A detection limit of 0.1 ng/mL1 ppb was achieved and good device reliability and repeatability were demonstrated. The novel microfluidic-based beadstrapping device thus opens up a new pathway to design micro-bead based biosensor immunoassays for clinical and othervarious applications.« less

Miniature PCR based portable bioaerosol monitor development.

PubMed

Agranovski, I E; Usachev, E V; Agranovski, E; Usacheva, O V

2017-01-01

A portable bioaerosol monitor is greatly demanded technology in many areas including air quality control, occupational exposure assessment and health risk evaluation, environmental studies and, especially, in defence and bio-terrorism applications. Our recent groundwork allowed us to formulate the concept of a portable bioaerosol monitor, which needs to be light, user friendly, reliable and capable of detecting airborne pathogens within 1-1·5 h on the spot. Conceptually, the event of a bioaerosol concentration burst is determined by triggers to commence the representative air sampling with sequential real-time polymerase chain reaction (PCR) confirmation of the targeted micro-organism present in the air. To minimize reagent consumption and idle running of the technology, an event of a bioaerosol burst is confirmed by three parameters: aerosol particle size, concentration and composition. Only particle sizes above 200 nm attract interest in the bioaerosol. Only an elevated aerosol concentration above the threshold (background aerosol concentration) is a signal to commence the analytical procedure. The combination of our previously developed personal bioaerosol sampler, aerosol particle counter based trigger and portable real-time PCR device formed the basis of the bioaerosol monitoring technology. The portable real-time PCR device was advanced to provide internally controlled detection, significantly reducing false-positive alarms. The technique is capable of detecting selected airborne micro-organisms on the spot within 30-80 min, depending on the genome organization of the particular strain. Due to recent outbreaks of infectious airborne diseases and the continuing threat of intentionally released bioaerosol attacks, investigations into the possibility of the early and reliable detection of pathogenic micro-organisms in the air is becoming increasingly important. The proposed technology consisting of a bioaerosol sampler, technology trigger and PCR device is capable of detecting selected airborne micro-organisms on the spot within a short time period. Journal of Applied Microbiology © 2016 The Society for Applied Microbiology.

Selective and reversible ammonia gas detection with nanoporous film functionalized silicon photonic micro-ring resonator.

PubMed

Yebo, Nebiyu A; Sree, Sreeprasanth Pulinthanathu; Levrau, Elisabeth; Detavernier, Christophe; Hens, Zeger; Martens, Johan A; Baets, Roel

2012-05-21

Portable, low cost and real-time gas sensors have a considerable potential in various biomedical and industrial applications. For such applications, nano-photonic gas sensors based on standard silicon fabrication technology offer attractive opportunities. Deposition of high surface area nano-porous coatings on silicon photonic sensors is a means to achieve selective, highly sensitive and multiplexed gas detection on an optical chip. Here we demonstrate selective and reversible ammonia gas detection with functionalized silicon-on-insulator optical micro-ring resonators. The micro-ring resonators are coated with acidic nano-porous aluminosilicate films for specific ammonia sensing, which results in a reversible response to NH(3)with selectivity relative to CO(2). The ammonia detection limit is estimated at about 5 ppm. The detectors reach a steady response to NH(3) within 30 and return to their base level within 60 to 90 seconds. The work opens perspectives on development of nano-photonic sensors for real-time, non-invasive, low cost and light weight biomedical and industrial sensing applications.

Growth and Characterization of Pyrite Thin Films for Photovoltaic Applications

NASA Astrophysics Data System (ADS)

Wertheim, Alex

A series of pyrite thin films were synthesized using a novel sequential evaporation technique to study the effects of substrate temperature on deposition rate and micro-structure of the deposited material. Pyrite was deposited in a monolayer-by-monolayer fashion using sequential evaporation of Fe under high vacuum, followed by sulfidation at high S pressures (typically > 1 mTorr to 1 Torr). Thin films were synthesized using two different growth processes; a one-step process in which a constant growth temperature is maintained throughout growth, and a three-step process in which an initial low temperature seed layer is deposited, followed by a high temperature layer, and then finished with a low temperature capping layer. Analysis methods to analyze the properties of the films included Glancing Angle X-Ray Diffraction (GAXRD), Rutherford Back-scattering Spectroscopy (RBS), Transmission Electron Microscopy (TEM), Secondary Ion Mass Spectroscopy (SIMS), 2-point IV measurements, and Hall effect measurements. Our results show that crystallinity of the pyrite thin film improves and grain size increases with increasing substrate temperature. The sticking coefficient of Fe was found to increase with increasing growth temperature, indicating that the Fe incorporation into the growing film is a thermally activated process.

An interactive web-based application for Comprehensive Analysis of RNAi-screen Data.

PubMed

Dutta, Bhaskar; Azhir, Alaleh; Merino, Louis-Henri; Guo, Yongjian; Revanur, Swetha; Madhamshettiwar, Piyush B; Germain, Ronald N; Smith, Jennifer A; Simpson, Kaylene J; Martin, Scott E; Buehler, Eugen; Beuhler, Eugen; Fraser, Iain D C

2016-02-23

RNAi screens are widely used in functional genomics. Although the screen data can be susceptible to a number of experimental biases, many of these can be corrected by computational analysis. For this purpose, here we have developed a web-based platform for integrated analysis and visualization of RNAi screen data named CARD (for Comprehensive Analysis of RNAi Data; available at https://card.niaid.nih.gov). CARD allows the user to seamlessly carry out sequential steps in a rigorous data analysis workflow, including normalization, off-target analysis, integration of gene expression data, optimal thresholds for hit selection and network/pathway analysis. To evaluate the utility of CARD, we describe analysis of three genome-scale siRNA screens and demonstrate: (i) a significant increase both in selection of subsequently validated hits and in rejection of false positives, (ii) an increased overlap of hits from independent screens of the same biology and (iii) insight to microRNA (miRNA) activity based on siRNA seed enrichment.

An interactive web-based application for Comprehensive Analysis of RNAi-screen Data

PubMed Central

Dutta, Bhaskar; Azhir, Alaleh; Merino, Louis-Henri; Guo, Yongjian; Revanur, Swetha; Madhamshettiwar, Piyush B.; Germain, Ronald N.; Smith, Jennifer A.; Simpson, Kaylene J.; Martin, Scott E.; Beuhler, Eugen; Fraser, Iain D. C.

2016-01-01

RNAi screens are widely used in functional genomics. Although the screen data can be susceptible to a number of experimental biases, many of these can be corrected by computational analysis. For this purpose, here we have developed a web-based platform for integrated analysis and visualization of RNAi screen data named CARD (for Comprehensive Analysis of RNAi Data; available at https://card.niaid.nih.gov). CARD allows the user to seamlessly carry out sequential steps in a rigorous data analysis workflow, including normalization, off-target analysis, integration of gene expression data, optimal thresholds for hit selection and network/pathway analysis. To evaluate the utility of CARD, we describe analysis of three genome-scale siRNA screens and demonstrate: (i) a significant increase both in selection of subsequently validated hits and in rejection of false positives, (ii) an increased overlap of hits from independent screens of the same biology and (iii) insight to microRNA (miRNA) activity based on siRNA seed enrichment. PMID:26902267

The graphics and data acquisition software package

NASA Technical Reports Server (NTRS)

Crosier, W. G.

1981-01-01

A software package was developed for use with micro and minicomputers, particularly the LSI-11/DPD-11 series. The package has a number of Fortran-callable subroutines which perform a variety of frequently needed tasks for biomedical applications. All routines are well documented, flexible, easy to use and modify, and require minimal programmer knowledge of peripheral hardware. The package is also economical of memory and CPU time. A single subroutine call can perform any one of the following functions: (1) plot an array of integer values from sampled A/D data, (2) plot an array of Y values versus an array of X values; (3) draw horizontal and/or vertical grid lines of selectable type; (4) annotate grid lines with user units; (5) get coordinates of user controlled crosshairs from the terminal for interactive graphics; (6) sample any analog channel with program selectable gain; (7) wait a specified time interval, and (8) perform random access I/O of one or more blocks of a sequential disk file. Several miscellaneous functions are also provided.

Localized mold heating with the aid of selective induction for injection molding of high aspect ratio micro-features

NASA Astrophysics Data System (ADS)

Park, Keun; Lee, Sang-Ik

2010-03-01

High-frequency induction is an efficient, non-contact means of heating the surface of an injection mold through electromagnetic induction. Because the procedure allows for the rapid heating and cooling of mold surfaces, it has been recently applied to the injection molding of thin-walled parts or micro/nano-structures. The present study proposes a localized heating method involving the selective use of mold materials to enhance the heating efficiency of high-frequency induction heating. For localized induction heating, a composite injection mold of ferromagnetic material and paramagnetic material is used. The feasibility of the proposed heating method is investigated through numerical analyses in terms of its heating efficiency for localized mold surfaces and in terms of the structural safety of the composite mold. The moldability of high aspect ratio micro-features is then experimentally compared under a variety of induction heating conditions.

Advancing three-dimensional MEMS by complimentary laser micro manufacturing

NASA Astrophysics Data System (ADS)

Palmer, Jeremy A.; Williams, John D.; Lemp, Tom; Lehecka, Tom M.; Medina, Francisco; Wicker, Ryan B.

2006-01-01

This paper describes improvements that enable engineers to create three-dimensional MEMS in a variety of materials. It also provides a means for selectively adding three-dimensional, high aspect ratio features to pre-existing PMMA micro molds for subsequent LIGA processing. This complimentary method involves in situ construction of three-dimensional micro molds in a stand-alone configuration or directly adjacent to features formed by x-ray lithography. Three-dimensional micro molds are created by micro stereolithography (MSL), an additive rapid prototyping technology. Alternatively, three-dimensional features may be added by direct femtosecond laser micro machining. Parameters for optimal femtosecond laser micro machining of PMMA at 800 nanometers are presented. The technical discussion also includes strategies for enhancements in the context of material selection and post-process surface finish. This approach may lead to practical, cost-effective 3-D MEMS with the surface finish and throughput advantages of x-ray lithography. Accurate three-dimensional metal microstructures are demonstrated. Challenges remain in process planning for micro stereolithography and development of buried features following femtosecond laser micro machining.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

DOEpatents

Chum, H.L.; Evans, R.J.

1992-08-04

A process is described for using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent. 11 figs.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

DOEpatents

Chum, Helena L.; Evans, Robert J.

1992-01-01

A process of using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent.

The Oenological Potential of Hanseniaspora uvarum in Simultaneous and Sequential Co-fermentation with Saccharomyces cerevisiae for Industrial Wine Production

PubMed Central

Tristezza, Mariana; Tufariello, Maria; Capozzi, Vittorio; Spano, Giuseppe; Mita, Giovanni; Grieco, Francesco

2016-01-01

In oenology, the utilization of mixed starter cultures composed by Saccharomyces and non-Saccharomyces yeasts is an approach of growing importance for winemakers in order to enhance sensory quality and complexity of the final product without compromising the general quality and safety of the oenological products. In fact, several non-Saccharomyces yeasts are already commercialized as oenological starter cultures to be used in combination with Saccharomyces cerevisiae, while several others are the subject of various studies to evaluate their application. Our aim, in this study was to assess, for the first time, the oenological potential of H. uvarum in mixed cultures (co-inoculation) and sequential inoculation with S. cerevisiae for industrial wine production. Three previously characterized H. uvarum strains were separately used as multi-starter together with an autochthonous S. cerevisiae starter culture in lab-scale micro-vinification trials. On the basis of microbial development, fermentation kinetics and secondary compounds formation, the strain H. uvarum ITEM8795 was further selected and it was co- and sequentially inoculated, jointly with the S. cerevisiae starter, in a pilot scale wine production. The fermentation course and the quality of final product indicated that the co-inoculation was the better performing modality of inoculum. The above results were finally validated by performing an industrial scale vinification The mixed starter was able to successfully dominate the different stages of the fermentation process and the H. uvarum strain ITEM8795 contributed to increasing the wine organoleptic quality and to simultaneously reduce the volatile acidity. At the best of our knowledge, the present report is the first study regarding the utilization of a selected H. uvarum strain in multi-starter inoculation with S. cerevisiae for the industrial production of a wine. In addition, we demonstrated, at an industrial scale, the importance of non-Saccharomyces in the design of tailored starter cultures for typical wines. PMID:27242698

The Oenological Potential of Hanseniaspora uvarum in Simultaneous and Sequential Co-fermentation with Saccharomyces cerevisiae for Industrial Wine Production.

PubMed

Tristezza, Mariana; Tufariello, Maria; Capozzi, Vittorio; Spano, Giuseppe; Mita, Giovanni; Grieco, Francesco

2016-01-01

In oenology, the utilization of mixed starter cultures composed by Saccharomyces and non-Saccharomyces yeasts is an approach of growing importance for winemakers in order to enhance sensory quality and complexity of the final product without compromising the general quality and safety of the oenological products. In fact, several non-Saccharomyces yeasts are already commercialized as oenological starter cultures to be used in combination with Saccharomyces cerevisiae, while several others are the subject of various studies to evaluate their application. Our aim, in this study was to assess, for the first time, the oenological potential of H. uvarum in mixed cultures (co-inoculation) and sequential inoculation with S. cerevisiae for industrial wine production. Three previously characterized H. uvarum strains were separately used as multi-starter together with an autochthonous S. cerevisiae starter culture in lab-scale micro-vinification trials. On the basis of microbial development, fermentation kinetics and secondary compounds formation, the strain H. uvarum ITEM8795 was further selected and it was co- and sequentially inoculated, jointly with the S. cerevisiae starter, in a pilot scale wine production. The fermentation course and the quality of final product indicated that the co-inoculation was the better performing modality of inoculum. The above results were finally validated by performing an industrial scale vinification The mixed starter was able to successfully dominate the different stages of the fermentation process and the H. uvarum strain ITEM8795 contributed to increasing the wine organoleptic quality and to simultaneously reduce the volatile acidity. At the best of our knowledge, the present report is the first study regarding the utilization of a selected H. uvarum strain in multi-starter inoculation with S. cerevisiae for the industrial production of a wine. In addition, we demonstrated, at an industrial scale, the importance of non-Saccharomyces in the design of tailored starter cultures for typical wines.

High speed micro scanner for 3D in-volume laser micro processing

NASA Astrophysics Data System (ADS)

Schaefer, D.; Gottmann, J.; Hermans, M.; Ortmann, J.; Kelbassa, I.

2013-03-01

Using an in-house developed micro scanner three-dimensional micro components and micro fluidic devices in fused silica are realized using the ISLE process (in-volume selective laser-induced etching). With the micro scanner system the potential of high average power femtosecond lasers (P > 100 W) is exploited by the fabrication of components with micrometer precision at scan speeds of several meters per second. A commercially available galvanometer scanner is combined with an acousto-optical and/or electro-optical beam deflector and translation stages. For focusing laser radiation high numerical aperture microscope objectives (NA > 0.3) are used generating a focal volume of a few cubic micrometers. After laser exposure the materials are chemically wet etched in aqueous solution. The laser-exposed material is etched whereas the unexposed material remains nearly unchanged. Using the described technique called ISLE the fabrication of three-dimensional micro components, micro holes, cuts and channels is possible with high average power femtosecond lasers resulting in a reduced processing time for exposure. By developing the high speed micro scanner up-scaling of the ISLE process is demonstrated. The fabricated components made out of glass can be applied in various markets like biological and medical diagnostics as well as in micro mechanics.

Facile Large-scale synthesis of stable CuO nanoparticles

NASA Astrophysics Data System (ADS)

Nazari, P.; Abdollahi-Nejand, B.; Eskandari, M.; Kohnehpoushi, S.

2018-04-01

In this work, a novel approach in synthesizing the CuO nanoparticles was introduced. A sequential corrosion and detaching was proposed in the growth and dispersion of CuO nanoparticles in the optimum pH value of eight. The produced CuO nanoparticles showed six nm (±2 nm) in diameter and spherical feather with a high crystallinity and uniformity in size. In this method, a large-scale production of CuO nanoparticles (120 grams in an experimental batch) from Cu micro-particles was achieved which may met the market criteria for large-scale production of CuO nanoparticles.

Delay test generation for synchronous sequential circuits

NASA Astrophysics Data System (ADS)

Devadas, Srinivas

1989-05-01

We address the problem of generating tests for delay faults in non-scan synchronous sequential circuits. Delay test generation for sequential circuits is a considerably more difficult problem than delay testing of combinational circuits and has received much less attention. In this paper, we present a method for generating test sequences to detect delay faults in sequential circuits using the stuck-at fault sequential test generator STALLION. The method is complete in that it will generate a delay test sequence for a targeted fault given sufficient CPU time, if such a sequence exists. We term faults for which no delay test sequence exists, under out test methodology, sequentially delay redundant. We describe means of eliminating sequential delay redundancies in logic circuits. We present a partial-scan methodology for enhancing the testability of difficult-to-test of untestable sequential circuits, wherein a small number of flip-flops are selected and made controllable/observable. The selection process guarantees the elimination of all sequential delay redundancies. We show that an intimate relationship exists between state assignment and delay testability of a sequential machine. We describe a state assignment algorithm for the synthesis of sequential machines with maximal delay fault testability. Preliminary experimental results using the test generation, partial-scan and synthesis algorithm are presented.

Multi-category micro-milling tool wear monitoring with continuous hidden Markov models

NASA Astrophysics Data System (ADS)

Zhu, Kunpeng; Wong, Yoke San; Hong, Geok Soon

2009-02-01

In-process monitoring of tool conditions is important in micro-machining due to the high precision requirement and high tool wear rate. Tool condition monitoring in micro-machining poses new challenges compared to conventional machining. In this paper, a multi-category classification approach is proposed for tool flank wear state identification in micro-milling. Continuous Hidden Markov models (HMMs) are adapted for modeling of the tool wear process in micro-milling, and estimation of the tool wear state given the cutting force features. For a noise-robust approach, the HMM outputs are connected via a medium filter to minimize the tool state before entry into the next state due to high noise level. A detailed study on the selection of HMM structures for tool condition monitoring (TCM) is presented. Case studies on the tool state estimation in the micro-milling of pure copper and steel demonstrate the effectiveness and potential of these methods.

High-throughput and reliable protocols for animal microRNA library cloning.

PubMed

Xiao, Caide

2011-01-01

MicroRNAs are short single-stranded RNA molecules (18-25 nucleotides). Because of their ability to silence gene expressions, they can be used to diagnose and treat tumors. Experimental construction of microRNA libraries was the most important step to identify microRNAs from animal tissues. Although there are many commercial kits with special protocols to construct microRNA libraries, this chapter provides the most reliable, high-throughput, and affordable protocols for microRNA library construction. The high-throughput capability of our protocols came from a double concentration (3 and 15%, thickness 1.5 mm) polyacrylamide gel electrophoresis (PAGE), which could directly extract microRNA-size RNAs from up to 400 μg total RNA (enough for two microRNA libraries). The reliability of our protocols was assured by a third PAGE, which selected PCR products of microRNA-size RNAs ligated with 5' and 3' linkers by a miRCat™ kit. Also, a MathCAD program was provided to automatically search short RNAs inserted between 5' and 3' linkers from thousands of sequencing text files.

The effect of lineup member similarity on recognition accuracy in simultaneous and sequential lineups.

PubMed

Flowe, Heather D; Ebbesen, Ebbe B

2007-02-01

Two experiments investigated whether remembering is affected by the similarity of the study face relative to the alternatives in a lineup. In simultaneous and sequential lineups, choice rates and false alarms were larger in low compared to high similarity lineups, indicating criterion placement was affected by lineup similarity structure (Experiment 1). In Experiment 2, foil choices and similarity ranking data for target present lineups were compared to responses made when the target was removed from the lineup (only the 5 foils were presented). The results indicated that although foils were selected more often in target-removed lineups in the simultaneous compared to the sequential condition, responses shifted from the target to one of the foils at equal rates across lineup procedures.

Study of Transport Characteristics of Motile Microorganisms Using Micro-Scale Devices

NASA Astrophysics Data System (ADS)

Parashar, R.; Scheibe, T. D.; Plymale, A.; Hu, D.; Kelly, R.; Frederick, J. M.; Yang, X.; Sund, N. L.

2016-12-01

Accurate numerical models of microbial transport are needed to support design and evaluation of bioremediation implementations. A sequence of micro-scale experiments using advanced microfluidics and imaging techniques was conducted to quantify the movement patterns of individual microbes and their interactions with solid surfaces in unobstructed medium and simple pore geometries. The set of bacteria studied encompasses strictly anaerobic, facultatively anaerobic, fermentative, and facultatively autotrophic species, with capacities to reduce a range of metals and radionuclides, as well as nitrate, using a variety of electron donors, including acetate, lactate, carbohydrates, and molecular hydrogen. Motion of motile microorganisms recorded over time provides results that can be analyzed to determine the character and several statistical attributes of microbial motion. Individual tracks on the order of several seconds to a few minutes in duration are characterized to provide information on 1) the length (distance in microns) of microbial runs, 2) velocity distributions along individual trajectories, and 3) the angle between the directions of sequential runs. Analysis of the microbial trajectories elucidates parameters related to dynamics of their motion. Comparison of these parameters with those of a classical Brownian motion yields crucial information on selection of appropriate model to account for microbial motility in relevant applications.

Bis-reaction-trigger as a strategy to improve the selectivity of fluorescent probes.

PubMed

Li, Dan; Cheng, Juan; Wang, Cheng-Kun; Ying, Huazhou; Hu, Yongzhou; Han, Feng; Li, Xin

2018-06-01

By the strategy of equipping a fluorophore with two reaction triggers that are tailored to the specific chemistry of peroxynitrite, we have developed a highly selective probe for detecting peroxynitrite in live cells. Sequential response by the two triggers enabled the probe to reveal various degrees of nitrosative stress in live cells via a sensitive emission colour change.

Computational approach for elucidating interactions of cross-species miRNAs and their targets in Flaviviruses.

PubMed

Shinde, Santosh P; Banerjee, Amit Kumar; Arora, Neelima; Murty, U S N; Sripathi, Venkateswara Rao; Pal-Bhadra, Manika; Bhadra, Utpal

2015-03-01

Combating viral diseases has been a challenging task since time immemorial. Available molecular approaches are limited and not much effective for this daunting task. MicroRNA based therapies have shown promise in recent times. MicroRNAs are tiny non-coding RNAs that regulate translational repression of target mRNA in highly specific manner. In this study, we have determined the target regions for human and viral microRNAs in the conserved genomic regions of selected viruses of Flaviviridae family using miRanda and performed a comparative target selectivity analysis among them. Specific target regions were determined and they were compared extensively among themselves by exploring their position to determine the vicinity. Based on the multiplicity and cooperativity analysis, interaction maps were developed manually to represent the interactions between top-ranking miRNAs and genomes of the viruses considered in this study. Self-organizing map (SOM) was used to cluster the best-ranked microRNAs based on the vital physicochemical properties. This study will provide deep insight into the interrelation of the viral and human microRNAs interactions with the selected Flaviviridae genomes and will help to identify cross-species microRNA targets on the viral genome.

Boronic Acid Functionalized Au Nanoparticles for Selective MicroRNA Signal Amplification in Fiber-Optic Surface Plasmon Resonance Sensing System.

PubMed

Qian, Siyu; Lin, Ming; Ji, Wei; Yuan, Huizhen; Zhang, Yang; Jing, Zhenguo; Zhao, Jianzhang; Masson, Jean-François; Peng, Wei

2018-05-25

MicroRNA (miRNA) regulates gene expression and plays a fundamental role in multiple biological processes. However, if both single-stranded RNA and DNA can bind with capture DNA on the sensing surface, selectively amplifying the complementary RNA signal is still challenging for researchers. Fiber-optic surface plasmon resonance (SPR) sensors are small, accurate, and convenient tools for monitoring biological interaction. In this paper, we present a high sensitivity microRNA detection technique using phenylboronic acid functionalized Au nanoparticles (PBA-AuNPs) in fiber-optic SPR sensing systems. Due to the inherent difficulty directly detecting the hybridized RNA on the sensing surface, the PBA-AuNPs were used to selectively amplify the signal of target miRNA. The result shows that the method has high selectivity and sensitivity for miRNA, with a detection limit at 2.7 × 10 -13 M (0.27 pM). This PBA-AuNPs amplification strategy is universally applicable for RNA detection with various sensing technologies, such as surface-enhanced Raman spectroscopy and electrochemistry, among others.

Universal, colorimetric microRNA detection strategy based on target-catalyzed toehold-mediated strand displacement reaction

NASA Astrophysics Data System (ADS)

Park, Yeonkyung; Lee, Chang Yeol; Kang, Shinyoung; Kim, Hansol; Park, Ki Soo; Park, Hyun Gyu

2018-02-01

In this work, we developed a novel, label-free, and enzyme-free strategy for the colorimetric detection of microRNA (miRNA), which relies on a target-catalyzed toehold-mediated strand displacement (TMSD) reaction. The system employs a detection probe that specifically binds to the target miRNA and sequentially releases a catalyst strand (CS) intended to trigger the subsequent TMSD reaction. Thus, the presence of target miRNA releases the CS that mediates the formation of an active G-quadruplex DNAzyme which is initially caged and inactivated by a blocker strand. In addition, a fuel strand that is supplemented for the recycling of the CS promotes another TMSD reaction, consequently generating a large number of active G-quadruplex DNAzymes. As a result, a distinct colorimetric signal is produced by the ABTS oxidation promoted by the peroxidase mimicking activity of the released G-quadruplex DNAzymes. Based on this novel strategy, we successfully detected miR-141, a promising biomarker for human prostate cancer, with high selectivity. The diagnostic capability of this system was also demonstrated by reliably determining target miR-141 in human serum, showing its great potential towards real clinical applications. Importantly, the proposed approach is composed of separate target recognition and signal transduction modules. Thus, it could be extended to analyze different target miRNAs by simply redesigning the detection probe while keeping the same signal transduction module as a universal signal amplification unit, which was successfully demonstrated by analyzing another target miRNA, let-7d.

Universal, colorimetric microRNA detection strategy based on target-catalyzed toehold-mediated strand displacement reaction.

PubMed

Park, Yeonkyung; Lee, Chang Yeol; Kang, Shinyoung; Kim, Hansol; Park, Ki Soo; Park, Hyun Gyu

2018-02-23

In this work, we developed a novel, label-free, and enzyme-free strategy for the colorimetric detection of microRNA (miRNA), which relies on a target-catalyzed toehold-mediated strand displacement (TMSD) reaction. The system employs a detection probe that specifically binds to the target miRNA and sequentially releases a catalyst strand (CS) intended to trigger the subsequent TMSD reaction. Thus, the presence of target miRNA releases the CS that mediates the formation of an active G-quadruplex DNAzyme which is initially caged and inactivated by a blocker strand. In addition, a fuel strand that is supplemented for the recycling of the CS promotes another TMSD reaction, consequently generating a large number of active G-quadruplex DNAzymes. As a result, a distinct colorimetric signal is produced by the ABTS oxidation promoted by the peroxidase mimicking activity of the released G-quadruplex DNAzymes. Based on this novel strategy, we successfully detected miR-141, a promising biomarker for human prostate cancer, with high selectivity. The diagnostic capability of this system was also demonstrated by reliably determining target miR-141 in human serum, showing its great potential towards real clinical applications. Importantly, the proposed approach is composed of separate target recognition and signal transduction modules. Thus, it could be extended to analyze different target miRNAs by simply redesigning the detection probe while keeping the same signal transduction module as a universal signal amplification unit, which was successfully demonstrated by analyzing another target miRNA, let-7d.

Automatic transducer switching provides accurate wide range measurement of pressure differential

NASA Technical Reports Server (NTRS)

Yoder, S. K.

1967-01-01

Automatic pressure transducer switching network sequentially selects any one of a number of limited-range transducers as gas pressure rises or falls, extending the range of measurement and lessening the chances of damage due to high pressure.

Identification of novel microRNA genes in freshwater and marine ecotypes of the three-spined stickleback (Gasterosteus aculeatus).

PubMed

Rastorguev, S M; Nedoluzhko, A V; Sharko, F S; Boulygina, E S; Sokolov, A S; Gruzdeva, N M; Skryabin, K G; Prokhortchouk, E B

2016-11-01

The three-spined stickleback (Gasterosteus aculeatus L.) is an important model organism for studying the molecular mechanisms of speciation and adaptation to salinity. Despite increased interest to microRNA discovery and recent publication on microRNA prediction in the three-spined stickleback using bioinformatics approaches, there is still a lack of experimental support for these data. In this paper, high-throughput sequencing technology was applied to identify microRNA genes in gills of the three-spined stickleback. In total, 595 miRNA genes were discovered; half of them were predicted in previous computational studies and were confirmed here as microRNAs expressed in gill tissue. Moreover, 298 novel microRNA genes were identified. The presence of miRNA genes in selected 'divergence islands' was analysed and 10 miRNA genes were identified as not randomly located in 'divergence islands'. Regulatory regions of miRNA genes were found enriched with selective SNPs that may play a role in freshwater adaptation. © 2016 John Wiley & Sons Ltd.

Method of selective reduction of halodisilanes with alkyltin hydrides

DOEpatents

D'Errico, John J.; Sharp, Kenneth G.

1989-01-01

The invention relates to the selective and sequential reduction of halodisilanes by reacting these compounds at room temperature or below with trialkyltin hydrides or dialkyltin dihydrides without the use of free radical intermediates. The alkyltin hydrides selectively and sequentially reduce the Si-Cl, Si-Br or Si-I bonds while leaving intact the Si-Si and Si-F bonds present.

Plasma exosome microRNAs are indicative of breast cancer.

PubMed

Hannafon, Bethany N; Trigoso, Yvonne D; Calloway, Cameron L; Zhao, Y Daniel; Lum, David H; Welm, Alana L; Zhao, Zhizhuang J; Blick, Kenneth E; Dooley, William C; Ding, W Q

2016-09-08

microRNAs are promising candidate breast cancer biomarkers due to their cancer-specific expression profiles. However, efforts to develop circulating breast cancer biomarkers are challenged by the heterogeneity of microRNAs in the blood. To overcome this challenge, we aimed to develop a molecular profile of microRNAs specifically secreted from breast cancer cells. Our first step towards this direction relates to capturing and analyzing the contents of exosomes, which are small secretory vesicles that selectively encapsulate microRNAs indicative of their cell of origin. To our knowledge, circulating exosome microRNAs have not been well-evaluated as biomarkers for breast cancer diagnosis or monitoring. Exosomes were collected from the conditioned media of human breast cancer cell lines, mouse plasma of patient-derived orthotopic xenograft models (PDX), and human plasma samples. Exosomes were verified by electron microscopy, nanoparticle tracking analysis, and western blot. Cellular and exosome microRNAs from breast cancer cell lines were profiled by next-generation small RNA sequencing. Plasma exosome microRNA expression was analyzed by qRT-PCR analysis. Small RNA sequencing and qRT-PCR analysis showed that several microRNAs are selectively encapsulated or highly enriched in breast cancer exosomes. Importantly, the selectively enriched exosome microRNA, human miR-1246, was detected at significantly higher levels in exosomes isolated from PDX mouse plasma, indicating that tumor exosome microRNAs are released into the circulation and can serve as plasma biomarkers for breast cancer. This observation was extended to human plasma samples where miR-1246 and miR-21 were detected at significantly higher levels in the plasma exosomes of 16 patients with breast cancer as compared to the plasma exosomes of healthy control subjects. Receiver operating characteristic curve analysis indicated that the combination of plasma exosome miR-1246 and miR-21 is a better indicator of breast cancer than their individual levels. Our results demonstrate that certain microRNA species, such as miR-21 and miR-1246, are selectively enriched in human breast cancer exosomes and significantly elevated in the plasma of patients with breast cancer. These findings indicate a potential new strategy to selectively analyze plasma breast cancer microRNAs indicative of the presence of breast cancer.

Analysis of filter tuning techniques for sequential orbit determination

NASA Technical Reports Server (NTRS)

Lee, T.; Yee, C.; Oza, D.

1995-01-01

This paper examines filter tuning techniques for a sequential orbit determination (OD) covariance analysis. Recently, there has been a renewed interest in sequential OD, primarily due to the successful flight qualification of the Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) using Doppler data extracted onboard the Extreme Ultraviolet Explorer (EUVE) spacecraft. TONS computes highly accurate orbit solutions onboard the spacecraft in realtime using a sequential filter. As the result of the successful TONS-EUVE flight qualification experiment, the Earth Observing System (EOS) AM-1 Project has selected TONS as the prime navigation system. In addition, sequential OD methods can be used successfully for ground OD. Whether data are processed onboard or on the ground, a sequential OD procedure is generally favored over a batch technique when a realtime automated OD system is desired. Recently, OD covariance analyses were performed for the TONS-EUVE and TONS-EOS missions using the sequential processing options of the Orbit Determination Error Analysis System (ODEAS). ODEAS is the primary covariance analysis system used by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD). The results of these analyses revealed a high sensitivity of the OD solutions to the state process noise filter tuning parameters. The covariance analysis results show that the state estimate error contributions from measurement-related error sources, especially those due to the random noise and satellite-to-satellite ionospheric refraction correction errors, increase rapidly as the state process noise increases. These results prompted an in-depth investigation of the role of the filter tuning parameters in sequential OD covariance analysis. This paper analyzes how the spacecraft state estimate errors due to dynamic and measurement-related error sources are affected by the process noise level used. This information is then used to establish guidelines for determining optimal filter tuning parameters in a given sequential OD scenario for both covariance analysis and actual OD. Comparisons are also made with corresponding definitive OD results available from the TONS-EUVE analysis.

Provoking Reflective Thinking in Post Observation Conversations

ERIC Educational Resources Information Center

Kim, Younhee; Silver, Rita Elaine

2016-01-01

We present a micro-analysis of post observation conversations between classroom teachers and mentors. Using the approach of conversation analysis, we show how the sequential organization of an episode (i.e., who initiates the interaction, question format used by mentors) could potentially serve to provoke or hinder teacher reflection. Our analysis…

Drug injection into fat tissue with a laser based microjet injector

NASA Astrophysics Data System (ADS)

Han, Tae-hee; Hah, Jung-moo; Yoh, Jack J.

2011-05-01

We have investigated a new micro drug jet injector using laser pulse energy. An infrared laser beam of high energy (˜3 J/pulse) is focused inside a driving fluid in a small chamber. The pulse then induces various energy releasing processes, and generates fast microjets through a micronozzle. The elastic membrane of this system plays an important role in transferring mechanical pressure and protecting drug from heat release. In this paper, we offer the sequential images of microjet generation taken by a high speed camera as an evidence of the multiple injections via single pulse. Furthermore, we test the proposed system to penetrate soft animal tissues in order to evaluate its feasibility as an advanced transdermal drug delivery method.

Applying a foil queue micro-electrode in micro-EDM to fabricate a 3D micro-structure

NASA Astrophysics Data System (ADS)

Xu, Bin; Guo, Kang; Wu, Xiao-yu; Lei, Jian-guo; Liang, Xiong; Guo, Deng-ji; Ma, Jiang; Cheng, Rong

2018-05-01

Applying a 3D micro-electrode in a micro electrical discharge machining (micro-EDM) can fabricate a 3D micro-structure with an up and down reciprocating method. However, this processing method has some shortcomings, such as a low success rate and a complex process for fabrication of 3D micro-electrodes. By focusing on these shortcomings, this paper proposed a novel 3D micro-EDM process based on the foil queue micro-electrode. Firstly, a 3D micro-electrode was discretized into several foil micro-electrodes and these foil micro-electrodes constituted a foil queue micro-electrode. Then, based on the planned process path, foil micro-electrodes were applied in micro-EDM sequentially and the micro-EDM results of each foil micro-electrode were able to superimpose the 3D micro-structure. However, the step effect will occur on the 3D micro-structure surface, which has an adverse effect on the 3D micro-structure. To tackle this problem, this paper proposes to reduce this adverse effect by rounded corner wear at the end of the foil micro-electrode and studies the impact of machining parameters on rounded corner wear and the step effect on the micro-structure surface. Finally, using a wire cutting voltage of 80 V, a current of 0.5 A and a pulse width modulation ratio of 1:4, the foil queue micro-electrode was fabricated by wire electrical discharge machining. Also, using a pulse width of 100 ns, a pulse interval of 200 ns, a voltage of 100 V and workpiece material of 304# stainless steel, the foil queue micro-electrode was applied in micro-EDM for processing of a 3D micro-structure with hemispherical features, which verified the feasibility of this process.

Prediction of novel pre-microRNAs with high accuracy through boosting and SVM.

PubMed

Zhang, Yuanwei; Yang, Yifan; Zhang, Huan; Jiang, Xiaohua; Xu, Bo; Xue, Yu; Cao, Yunxia; Zhai, Qian; Zhai, Yong; Xu, Mingqing; Cooke, Howard J; Shi, Qinghua

2011-05-15

High-throughput deep-sequencing technology has generated an unprecedented number of expressed short sequence reads, presenting not only an opportunity but also a challenge for prediction of novel microRNAs. To verify the existence of candidate microRNAs, we have to show that these short sequences can be processed from candidate pre-microRNAs. However, it is laborious and time consuming to verify these using existing experimental techniques. Therefore, here, we describe a new method, miRD, which is constructed using two feature selection strategies based on support vector machines (SVMs) and boosting method. It is a high-efficiency tool for novel pre-microRNA prediction with accuracy up to 94.0% among different species. miRD is implemented in PHP/PERL+MySQL+R and can be freely accessed at http://mcg.ustc.edu.cn/rpg/mird/mird.php.

Micro-columns packed with Chlorella vulgaris immobilised on silica gel for mercury speciation.

PubMed

Tajes-Martínez, P; Beceiro-González, E; Muniategui-Lorenzo, S; Prada-Rodríguez, D

2006-02-28

A method has been developed for mercury speciation in water by using columns packed with Chlorella vulgaris immobilised on silica gel. The method involves the retention of CH(3)Hg(+) and Hg(2+) in micro-columns prepared by packing immobilised algae in polypropylene tubes, followed by selective and sequential elution with 0.03 and 1.5M HCl for CH(3)Hg(+) and Hg(2+), respectively. The adsorption capacity of the micro-algae for Hg(2+) and CH(3)Hg(+) has been evaluated using free and immobilised C. vulgaris. The efficiency uptake for both species at pH 3 was higher than 97%. Studies were carried out on the effect of retention and elution conditions for both species. Furthermore, the stability of mercury species retained on algae-silica gel micro-columns and lifetime of the columns were also investigated. Hg(2+) showed a higher stability than CH(3)Hg(+) at 0 degrees C (21 and 3 days, respectively) and a better lifetime than for the organic species. The developed method was applied to the analysis of spiked tap, sea and wastewater samples. Recovery studies on tap and filtered seawater provided results between 96+/-3 and 106+/-2 for Hg(2+) and from 98+/-5 to 107+/-5 for CH(3)Hg(+), for samples spiked with single species. For samples spiked with both CH(3)Hg(+) and Hg(2+), the average recoveries varied from 96+/-5 to 99+/-3 and from 103+/-6 to 115+/-5 for Hg(2+) and CH(3)Hg(+), respectively. However, the percentages of retention and elution on wastewater and unfiltered seawater were only adequate for the inorganic species.

Up-conversion in rare-earth doped micro-particles applied to new emissive two-dimensional displays

NASA Astrophysics Data System (ADS)

Milliez, Anne Janet

Up-conversion (UC) in rare-earth co-doped fluorides to convert diode laser light in the near infrared to red, green and blue visible light is applied to make possible high performance emissive displays. The infrared-to-visible UC in the materials we study is a sequential form of non-linear two photon absorption in which a strong absorbing constituent absorbs two low energy photons and transfers this energy to another constituent which emits visible light. Some of the UC emitters' most appealing characteristics for displays are: a wide color gamut with very saturated colors, very high brightness operation without damage to the emitters, long lifetimes and efficiencies comparable to those of existing technologies. Other advantages include simplicity of fabrication, versatility of operating modes, and the potential for greatly reduced display weight and depth. Thanks to recent advances in material science and diode laser technology at the excitation wavelength, UC selected materials can be very efficient visible emitters. However, optimal UC efficiencies strongly depend on chosing proper operating conditions. In this thesis, we studied the conditions required for optimization. We demonstrated that high efficiency UC depends on high pump irradiance, low temperature and low scattering. With this understanding we can predict how to optimally use UC emitters in a wide range of applications. In particular, we showed how our very efficient UC emitters can be applied to make full color displays and very efficient white light sources.

Self-regulated learning of important information under sequential and simultaneous encoding conditions.

PubMed

Middlebrooks, Catherine D; Castel, Alan D

2018-05-01

Learners make a number of decisions when attempting to study efficiently: they must choose which information to study, for how long to study it, and whether to restudy it later. The current experiments examine whether documented impairments to self-regulated learning when studying information sequentially, as opposed to simultaneously, extend to the learning of and memory for valuable information. In Experiment 1, participants studied lists of words ranging in value from 1-10 points sequentially or simultaneously at a preset presentation rate; in Experiment 2, study was self-paced and participants could choose to restudy. Although participants prioritized high-value over low-value information, irrespective of presentation, those who studied the items simultaneously demonstrated superior value-based prioritization with respect to recall, study selections, and self-pacing. The results of the present experiments support the theory that devising, maintaining, and executing efficient study agendas is inherently different under sequential formatting than simultaneous. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Quantum cascade light emitting diodes based on type-2 quantum wells

NASA Technical Reports Server (NTRS)

Lin, C. H.; Yang, R. Q.; Zhang, D.; Murry, S. J.; Pei, S. S.; Allerman, A. A.; Kurtz, S. R.

1997-01-01

The authors have demonstrated room-temperature CW operation of type-2 quantum cascade (QC) light emitting diodes at 4.2 (micro)m using InAs/InGaSb/InAlSb type-2 quantum wells. The type-2 QC configuration utilizes sequential multiple photon emissions in a staircase of coupled type-2 quantum wells. The device was grown by molecular beam epitaxy on a p-type GaSb substrate and was compared of 20 periods of active regions separated by digitally graded quantum well injection regions. The maximum average output power is about 250 (micro)W at 80 K, and 140 (micro)W at 300 K at a repetition rate of 1 kHz with a duty cycle of 50%.

A Cancer-Indicative microRNA Pattern in Normal Prostate Tissue

PubMed Central

Hellwinkel, Olaf J. C.; Sellier, Christina; Sylvester, Yu-Mi Jessica; Brase, Jan C.; Isbarn, Hendrik; Erbersdobler, Andreas; Steuber, Thomas; Sültmann, Holger; Schlomm, Thorsten; Wagner, Christina

2013-01-01

We analyzed the levels of selected micro-RNAs in normal prostate tissue to assess their potential to indicate tumor foci elsewhere in the prostate. Histologically normal prostate tissue samples from 31 prostate cancer patients and two cancer negative control groups with either unsuspicious or elevated prostate specific antigen (PSA) levels (14 and 17 individuals, respectively) were analyzed. Based on the expression analysis of 157 microRNAs in a pool of prostate tissue samples and information from data bases/literature, we selected eight microRNAs for quantification by real-time polymerase chain reactions (RT-PCRs). Selected miRNAs were analyzed in histologically tumor-free biopsy samples from patients and healthy controls. We identified seven microRNAs (miR-124a, miR-146a & b, miR-185, miR-16 and let-7a & b), which displayed significant differential expression in normal prostate tissue from men with prostate cancer compared to both cancer negative control groups. Four microRNAs (miR-185, miR-16 and let-7a and let-7b) remained to significantly discriminate normal tissues from prostate cancer patients from those of the cancer negative control group with elevated PSA levels. The transcript levels of these microRNAs were highly indicative for the presence of cancer in the prostates, independently of the PSA level. Our results suggest a microRNA-pattern in histologically normal prostate tissue, indicating prostate cancer elsewhere in the organ. PMID:23459235

Estimating Soil Moisture Using Polsar Data: a Machine Learning Approach

NASA Astrophysics Data System (ADS)

Khedri, E.; Hasanlou, M.; Tabatabaeenejad, A.

2017-09-01

Soil moisture is an important parameter that affects several environmental processes. This parameter has many important functions in numerous sciences including agriculture, hydrology, aerology, flood prediction, and drought occurrence. However, field procedures for moisture calculations are not feasible in a vast agricultural region territory. This is due to the difficulty in calculating soil moisture in vast territories and high-cost nature as well as spatial and local variability of soil moisture. Polarimetric synthetic aperture radar (PolSAR) imaging is a powerful tool for estimating soil moisture. These images provide a wide field of view and high spatial resolution. For estimating soil moisture, in this study, a model of support vector regression (SVR) is proposed based on obtained data from AIRSAR in 2003 in C, L, and P channels. In this endeavor, sequential forward selection (SFS) and sequential backward selection (SBS) are evaluated to select suitable features of polarized image dataset for high efficient modeling. We compare the obtained data with in-situ data. Output results show that the SBS-SVR method results in higher modeling accuracy compared to SFS-SVR model. Statistical parameters obtained from this method show an R2 of 97% and an RMSE of lower than 0.00041 (m3/m3) for P, L, and C channels, which has provided better accuracy compared to other feature selection algorithms.

Prediction of plant pre-microRNAs and their microRNAs in genome-scale sequences using structure-sequence features and support vector machine.

PubMed

Meng, Jun; Liu, Dong; Sun, Chao; Luan, Yushi

2014-12-30

MicroRNAs (miRNAs) are a family of non-coding RNAs approximately 21 nucleotides in length that play pivotal roles at the post-transcriptional level in animals, plants and viruses. These molecules silence their target genes by degrading transcription or suppressing translation. Studies have shown that miRNAs are involved in biological responses to a variety of biotic and abiotic stresses. Identification of these molecules and their targets can aid the understanding of regulatory processes. Recently, prediction methods based on machine learning have been widely used for miRNA prediction. However, most of these methods were designed for mammalian miRNA prediction, and few are available for predicting miRNAs in the pre-miRNAs of specific plant species. Although the complete Solanum lycopersicum genome has been published, only 77 Solanum lycopersicum miRNAs have been identified, far less than the estimated number. Therefore, it is essential to develop a prediction method based on machine learning to identify new plant miRNAs. A novel classification model based on a support vector machine (SVM) was trained to identify real and pseudo plant pre-miRNAs together with their miRNAs. An initial set of 152 novel features related to sequential structures was used to train the model. By applying feature selection, we obtained the best subset of 47 features for use with the Back Support Vector Machine-Recursive Feature Elimination (B-SVM-RFE) method for the classification of plant pre-miRNAs. Using this method, 63 features were obtained for plant miRNA classification. We then developed an integrated classification model, miPlantPreMat, which comprises MiPlantPre and MiPlantMat, to identify plant pre-miRNAs and their miRNAs. This model achieved approximately 90% accuracy using plant datasets from nine plant species, including Arabidopsis thaliana, Glycine max, Oryza sativa, Physcomitrella patens, Medicago truncatula, Sorghum bicolor, Arabidopsis lyrata, Zea mays and Solanum lycopersicum. Using miPlantPreMat, 522 Solanum lycopersicum miRNAs were identified in the Solanum lycopersicum genome sequence. We developed an integrated classification model, miPlantPreMat, based on structure-sequence features and SVM. MiPlantPreMat was used to identify both plant pre-miRNAs and the corresponding mature miRNAs. An improved feature selection method was proposed, resulting in high classification accuracy, sensitivity and specificity.

Use of High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS) for Sequential Multi-Element Determination of Metals in Seawater and Wastewater Samples

NASA Astrophysics Data System (ADS)

Peña-Vázquez, E.; Barciela-Alonso, M. C.; Pita-Calvo, C.; Domínguez-González, R.; Bermejo-Barrera, P.

2015-09-01

The objective of this work is to develop a method for the determination of metals in saline matrices using high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Module SFS 6 for sample injection was used in the manual mode, and flame operating conditions were selected. The main absorption lines were used for all the elements, and the number of selected analytical pixels were 5 (CP±2) for Cd, Cu, Fe, Ni, Pb and Zn, and 3 pixels for Mn (CP±1). Samples were acidified (0.5% (v/v) nitric acid), and the standard addition method was used for the sequential determination of the analytes in diluted samples (1:2). The method showed good precision (RSD(%) < 4%, except for Pb (6.5%)) and good recoveries. Accuracy was checked after the analysis of an SPS-WW2 wastewater reference material diluted with synthetic seawater (dilution 1:2), showing a good agreement between certified and experimental results.

Micro-surgical endodontics.

PubMed

Eliyas, S; Vere, J; Ali, Z; Harris, I

2014-02-01

Non-surgical endodontic retreatment is the treatment of choice for endodontically treated teeth with recurrent or residual disease in the majority of cases. In some cases, surgical endodontic treatment is indicated. Successful micro-surgical endodontic treatment depends on the accuracy of diagnosis, appropriate case selection, the quality of the surgical skills, and the application of the most appropriate haemostatic agents and biomaterials. This article describes the armamentarium and technical procedures involved in performing micro-surgical endodontics to a high standard.

Hydrothermally grown α-MnO2 interlocked mesoporous micro-cubes of several nanocrystals as selective and sensitive nitrogen dioxide chemoresistive gas sensors

NASA Astrophysics Data System (ADS)

Shinde, Pritamkumar V.; Xia, Qi Xun; Ghule, Balaji G.; Shinde, Nanasaheb M.; Seonghee, Jeong; Kim, Kwang Ho; Mane, Rajaram S.

2018-06-01

The interesting and multifunctional properties of alpha-manganese dioxide (α-MnO2) are considered to be highly sensitive and selective to nitrogen dioxide (NO2) chemresistive gas sensors. The α-MnO2 mesoporous interlocked micro-cubes composed of several interconnected nanocrystals synthesized by a facile and low-cost hydrothermal method on soda-lime glass substrate are envisaged as selective and sensitive NO2 gas sensors. Phase-purity and surface area with pore-size distribution are initially screened. The three-dimensional α-MnO2 mesoporous-cube-based gas sensors tested for NO2 gas from room-temperature (27 °C) to 250 °C have demonstrated 33% response for 100 ppm NO2 levels at 150 °C. The response and recovery time values of the α-MnO2 sensor are found to be 26 s and recovery 91 s, respectively, with high selectivity, good sensitivity, and considerable chemical and environmental stabilities, confirming the gas sensor applications potentiality of α-MnO2 morphology which is a combination of interlocked mesoporous micro-cubes and well-connected nanocrystals.

The Electromechanical Behavior of a Micro-Ring Driven by Traveling Electrostatic Force

PubMed Central

Ye, Xiuqian; Chen, Yibao; Chen, Da-Chih; Huang, Kuo-Yi; Hu, Yuh-Chung

2012-01-01

There is no literature mentioning the electromechanical behavior of micro structures driven by traveling electrostatic forces. This article is thus the first to present the dynamics and stabilities of a micro-ring subjected to a traveling electrostatic force. The traveling electrostatic force may be induced by sequentially actuated electrodes which are arranged around the flexible micro-ring. The analysis is based on a linearized distributed model considering the electromechanical coupling effects between electrostatic force and structure. The micro-ring will resonate when the traveling speeds of the electrostatic force approach some critical speeds. The critical speeds are equal to the ratio of the natural frequencies to the wave number of the correlative natural mode of the ring. Apart from resonance, the ring may be unstable at some unstable traveling speeds. The unstable regions appear not only near the critical speeds, but also near some fractions of some critical speeds differences. Furthermore the unstable regions expand with increasing driving voltage. This article may lead to a new research branch on electrostatic-driven micro devices. PMID:22438705

Sequential analysis applied to clinical trials in dentistry: a systematic review.

PubMed

Bogowicz, P; Flores-Mir, C; Major, P W; Heo, G

2008-01-01

Clinical trials employ sequential analysis for the ethical and economic benefits it brings. In dentistry, as in other fields, resources are scarce and efforts are made to ensure that patients are treated ethically. The objective of this systematic review was to characterise the use of sequential analysis for clinical trials in dentistry. We searched various databases from 1900 through to January 2008. Articles were selected for review if they were clinical trials in the field of dentistry that had applied some form of sequential analysis. Selection was carried out independently by two of the authors. We included 18 trials from various specialties, which involved many different interventions. We conclude that sequential analysis seems to be underused in this field but that there are sufficient methodological resources in place for future applications.Evidence-Based Dentistry (2008) 9, 55-62. doi:10.1038/sj.ebd.6400587.

Multi-Phenotypic subtyping of circulating tumor cells using sequential fluorescent quenching and restaining

NASA Astrophysics Data System (ADS)

Adams, Daniel L.; Alpaugh, R. Katherine; Tsai, Susan; Tang, Cha-Mei; Stefansson, Steingrimur

2016-09-01

In tissue biopsies formalin fixed paraffin embedded cancer blocks are micro-sectioned producing multiple semi-identical specimens which are analyzed and subtyped proteomically, and genomically, with numerous biomarkers. In blood based biopsies (BBBs), blood is purified for circulating tumor cells (CTCs) and clinical utility is typically limited to cell enumeration, as only 2-3 positive fluorescent markers and 1 negative marker can be used. As such, increasing the number of subtyping biomarkers on each individual CTC could dramatically enhance the clinical utility of BBBs, allowing in depth interrogation of clinically relevant CTCs. We describe a simple and inexpensive method for quenching the specific fluors of fluorescently stained CTCs followed by sequential restaining with additional biomarkers. As proof of principle a CTC panel, immunosuppression panel and stem cell panel were used to sequentially subtype individual fluorescently stained patient CTCs, suggesting a simple and universal technique to analyze multiple clinically applicable immunomarkers from BBBs.

Hyperbaric bupivacaine 2.5 mg prolongs analgesia compared with plain bupivacaine when added to intrathecal fentanyl 25 microg in advanced labor.

PubMed

Teoh, Wendy H L; Sia, Alex T H

2003-09-01

We investigated the effect of sequential administration of intrathecal (IT) hyperbaric bupivacaine (after the initial administration of IT hypobaric fentanyl) on the duration of spinal analgesia. Thirty-seven nulliparous parturients with a cervical dilation >/= 5 cm were randomized to receive either IT fentanyl 25 micro g and plain bupivacaine 2.5 mg (group P; n = 19) or IT fentanyl 25 micro g and hyperbaric (with 8% glucose) bupivacaine 2.5 mg (group H; n = 18). The two components of the IT injectate were administered sequentially (fentanyl 25 micro g diluted in 2 mL of normal saline, immediately followed by 0.5 mL of 0.5% bupivacaine). Patients were then positioned with their torso elevated at 30 degrees for 30 min. Pain scores using 0-100 visual analog scales were collected before combined spinal/epidural analgesia and at 5, 15, and 30 min after the block. Patients in Group H had a longer median duration of analgesia (122 min; range, 80-210 min) than Group P (95 min; range, 75-125 min) (P < 0.01). Group H also had a more limited dermatomal spread (median highest sensory level of T8 versus T4 in group P; P < 0.05). The side-effect profile was similar. Under these circumstances, hyperbaric bupivacaine conferred an increased duration of IT analgesia compared with plain bupivacaine.

Detection of microRNAs in color space.

PubMed

Marco, Antonio; Griffiths-Jones, Sam

2012-02-01

Deep sequencing provides inexpensive opportunities to characterize the transcriptional diversity of known genomes. The AB SOLiD technology generates millions of short sequencing reads in color-space; that is, the raw data is a sequence of colors, where each color represents 2 nt and each nucleotide is represented by two consecutive colors. This strategy is purported to have several advantages, including increased ability to distinguish sequencing errors from polymorphisms. Several programs have been developed to map short reads to genomes in color space. However, a number of previously unexplored technical issues arise when using SOLiD technology to characterize microRNAs. Here we explore these technical difficulties. First, since the sequenced reads are longer than the biological sequences, every read is expected to contain linker fragments. The color-calling error rate increases toward the 3(') end of the read such that recognizing the linker sequence for removal becomes problematic. Second, mapping in color space may lead to the loss of the first nucleotide of each read. We propose a sequential trimming and mapping approach to map small RNAs. Using our strategy, we reanalyze three published insect small RNA deep sequencing datasets and characterize 22 new microRNAs. A bash shell script to perform the sequential trimming and mapping procedure, called SeqTrimMap, is available at: http://www.mirbase.org/tools/seqtrimmap/ antonio.marco@manchester.ac.uk Supplementary data are available at Bioinformatics online.

Development of flow systems by direct-milling on poly(methyl methacrylate) substrates using UV-photopolymerization as sealing process.

PubMed

Rodrigues, Eunice R G O; Lapa, Rui A S

2009-03-01

An alternative process for the design and construction of fluidic devices is presented. Several sealing processes were studied, as well as the hydrodynamic characteristics of the proposed fluidic devices. Manifolds were imprinted on polymeric substrates by direct-write milling, according to Computer Assisted Design (CAD) data. Poly(methyl methacrylate) (PMMA) was used as substrate due to its physical and chemical properties. Different bonding approaches for the imprinted channels were evaluated and UV-photopolymerization of acrylic acid (AA) was selected. The hydrodynamic characteristics of the proposed flow devices were assessed and compared to those obtained in similar flow systems using PTFE reactors and micro-pumps as propulsion units (multi-pumping approach). The applicability of the imprinted reactors was evaluated in the sequential determination of calcium and magnesium in water samples. Results obtained were in good agreement with those obtained by the reference procedure.

The Interactional Management of Claims of Insufficient Knowledge in English Language Classrooms

ERIC Educational Resources Information Center

Sert, Olcay; Walsh, Steve

2013-01-01

This paper primarily investigates the interactional unfolding and management of "claims of insufficient knowledge" (Beach and Metzger 1997) in two English language classrooms from a multi-modal, conversation-analytic perspective. The analyses draw on a close, micro-analytic account of sequential organisation of talk as well as on various…

EDITORIAL: Selected papers from the 9th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2009) Selected papers from the 9th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2009)

NASA Astrophysics Data System (ADS)

Ghodssi, Reza; Livermore, Carol; Arnold, David

2010-10-01

This special section of the Journal of Micromechanics and Microengineering presents papers selected from the 9th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2009), which was held in Washington DC, USA from 1-4 December 2009. Since it was first held in Sendai, Japan in 2000, the PowerMEMS workshop has focused on small-scale systems that process, convert, or generate macroscopically significant amounts of power, typically with high power density or high energy density. In the workshop's early years, much of the research presented was on small-scale fueled systems, such as micro heat engines and micro fuel cells. The past nine years have seen a dramatic expansion in the range of technologies that are brought to bear on the challenge of high-power, small-scale systems, as well as an increase in the applications for such technologies. At this year's workshop, 158 contributed papers were presented, along with invited and plenary presentations. The papers focused on applications from micro heat engines and fuel cells, to energy harvesting and its enabling electronics, to thermal management and propulsion. Also presented were the technologies that enable these applications, such as the structuring of microscale, nanoscale and biological systems for power applications, as well as combustion and catalysis at small scales. This special section includes a selection of 12 expanded papers representing energy harvesting, chemical and fueled systems, and elastic energy storage at small scales. We would like to express our appreciation to the members of the International Steering Committee, the Technical Program Committee, the Local Organizing Committee, and to the workshop's financial supporters. We are grateful to the referees for their contributions to the review process. Finally, we would like to thank Dr Ian Forbes, the editorial staff of the Journal of Micromechanics and Microengineering, and the staff of IOP Publishing for making this special section possible.

Decoding-Accuracy-Based Sequential Dimensionality Reduction of Spatio-Temporal Neural Activities

NASA Astrophysics Data System (ADS)

Funamizu, Akihiro; Kanzaki, Ryohei; Takahashi, Hirokazu

Performance of a brain machine interface (BMI) critically depends on selection of input data because information embedded in the neural activities is highly redundant. In addition, properly selected input data with a reduced dimension leads to improvement of decoding generalization ability and decrease of computational efforts, both of which are significant advantages for the clinical applications. In the present paper, we propose an algorithm of sequential dimensionality reduction (SDR) that effectively extracts motor/sensory related spatio-temporal neural activities. The algorithm gradually reduces input data dimension by dropping neural data spatio-temporally so as not to undermine the decoding accuracy as far as possible. Support vector machine (SVM) was used as the decoder, and tone-induced neural activities in rat auditory cortices were decoded into the test tone frequencies. SDR reduced the input data dimension to a quarter and significantly improved the accuracy of decoding of novel data. Moreover, spatio-temporal neural activity patterns selected by SDR resulted in significantly higher accuracy than high spike rate patterns or conventionally used spatial patterns. These results suggest that the proposed algorithm can improve the generalization ability and decrease the computational effort of decoding.

Tachykinin receptors in the guinea-pig renal pelvis: activation by exogenous and endogenous tachykinins.

PubMed Central

Maggi, C. A.; Patacchini, R.; Eglezos, A.; Quartara, L.; Giuliani, S.; Giachetti, A.

1992-01-01

1. The contractile response to substance P, neurokinin A, selective agonists for the NK1, NK2 and NK3 tachykinin receptors and the activity of receptor-selective antagonists has been investigated in circular muscle strips of the guinea-pig isolated renal pelvis in the presence of indomethacin (3 microM). 2. Neurokinin A was the most potent agonist tested, being about 32 times more potent than substance P. The action of both substance P and neurokinin A was enhanced by peptidase inhibitors (bestatin, captopril and thiorphan, 1 microM each). The selective NK2 receptor agonist [beta Ala8] neurokinin A (4-10), was slightly less potent and effective than neurokinin A itself. The selective NK1 receptor agonist [Sar9] substance P sulphone was effective at low (nM) concentrations but its maximal effect did not exceed 30% of maximal response to substance P or neurokinin A. The NK3-selective agonist [MePhe7] neurokinin B was effective only at high (microM) concentrations. 3. The pseudopeptide derivative of neurokinin A(4-10), MDL 28,564, displayed a clear-cut agonist character, although it was less potent than neurokinin A. 4. The responses to roughly equieffective (25-35% of maximal response) concentrations of [beta Ala8] neurokinin A (4-10), MDL 28,564 and [MePhe7] neurokinin B were antagonized to a similar extent by MEN 10,376 (3 microM), a selective NK2 tachykinin receptor antagonist, while the response to [Sar9] substance P sulphone was unchanged. 5. The response to [Sar9] substance P sulphone was inhibited by the NK1 receptor-selective antagonist, GR 82,334 (3 microM) while the response to [beta Ala8] neurokinin A (4-10) was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1384907

The Nature, Causes and Effects of School Violence in South African High Schools

ERIC Educational Resources Information Center

Ncontsa, Vusumzi Nelson; Shumba, Almon

2013-01-01

We sought to investigate the nature, causes and effects of school violence in four South African high schools. A purposive sample of five principals, 80 learners and 20 educators was selected from the four schools used in the study. A sequential mixed method approach was used in this study; both questionnaires and interviews were used. The design…

A Bayesian Theory of Sequential Causal Learning and Abstract Transfer.

PubMed

Lu, Hongjing; Rojas, Randall R; Beckers, Tom; Yuille, Alan L

2016-03-01

Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause-effect links, or do learners also acquire knowledge about abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre-training (or even post-training) can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables (e.g., binary vs. continuous) to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue-outcome co-occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge. Copyright © 2015 Cognitive Science Society, Inc.

Human L-DOPA decarboxylase mRNA is a target of miR-145: A prediction to validation workflow.

PubMed

Papadopoulos, Emmanuel I; Fragoulis, Emmanuel G; Scorilas, Andreas

2015-01-10

l-DOPA decarboxylase (DDC) is a multiply-regulated gene which encodes the enzyme that catalyzes the biosynthesis of dopamine in humans. MicroRNAs comprise a novel class of endogenously transcribed small RNAs that can post-transcriptionally regulate the expression of various genes. Given that the mechanism of microRNA target recognition remains elusive, several genes, including DDC, have not yet been identified as microRNA targets. Nevertheless, a number of specifically designed bioinformatic algorithms provide candidate miRNAs for almost every gene, but still their results exhibit moderate accuracy and should be experimentally validated. Motivated by the above, we herein sought to discover a microRNA that regulates DDC expression. By using the current algorithms according to bibliographic recommendations we found that miR-145 could be predicted with high specificity as a candidate regulatory microRNA for DDC expression. Thus, a validation experiment followed by firstly transfecting an appropriate cell culture system with a synthetic miR-145 sequence and sequentially assessing the mRNA and protein levels of DDC via real-time PCR and Western blotting, respectively. Our analysis revealed that miR-145 had no significant impact on protein levels of DDC but managed to dramatically downregulate its mRNA expression. Overall, the experimental and bioinformatic analysis conducted herein indicate that miR-145 has the ability to regulate DDC mRNA expression and potentially this occurs by recognizing its mRNA as a target. Copyright © 2014. Published by Elsevier B.V.

High-Selectivity Electrochemical Conversion of CO 2 to Ethanol using a Copper Nanoparticle/N-Doped Graphene Electrode

DOE PAGES

Song, Yang; Peng, Rui; Hensley, Dale K.; ...

2016-09-28

Carbon dioxide is a pollutant, but also a potential carbon source provided an efficient means to convert it to useful products. Herein we report a nanostructured catalyst for the direct electrochemical reduction of dissolved CO 2 to ethanol with high Faradaic efficiency (63%) and high selectivity (84%). The catalyst is comprised of Cu nanoparticle on a highly textured, N-doped graphene film. Detailed electrochemical analysis and complementary DFT calculations indicate a novel mechanism in which multiple active sites, working sequentially, control the coupling of carbon monoxide radicals and mediate the subsequent electrochemical reduction to alcohol.

Polarized micro-cavity organic light-emitting devices.

PubMed

Park, Byoungchoo; Kim, Mina; Park, Chan Hyuk

2009-04-27

We present the results of a study of light emissions from a polarized micro-cavity Organic Light-Emitting Device (OLED), which consisted of a flexible, anisotropic one-dimensional (1-D) photonic crystal (PC) film substrate. It is shown that luminous Electroluminescent (EL) emissions from the polarized micro-cavity OLED were produced at relatively low operating voltages. It was also found that the peak wavelengths of the emitted EL light corresponded to the two split eigen modes of the high-energy band edges of the anisotropic PC film, with a strong dependence on the polarization state of the emitting light. For polarization along the ordinary axis of the anisotropic PC film, the optical split micro-cavity modes occurred at the longer high-energy photonic band gap (PBG) edge, while for polarization along the extraordinary axis, the split micro-cavity modes occurred at the shorter high-energy PBG edge, with narrow bandwidths. We demonstrated that the polarization and emission mode of the micro-cavity OLED may be selected by choosing the appropriate optical axis of the anisotropic 1-D PC film.

Neurokinin-induced changes in pial artery diameter in the anaesthetized guinea-pig.

PubMed Central

Beattie, D. T.; Stubbs, C. M.; Connor, H. E.; Feniuk, W.

1993-01-01

1. The effects of selective neurokinin agents on pial artery diameter, measured with an on-line image analyser, have been studied in anaesthetized guinea-pigs in order to characterize the neurokinin receptors present on pial arteries. 2. Perivascular injection of either substance P (0.01-1 microM) or the selective NK1 receptor agonists, substance P methyl ester (SPOMe, 0.01-1 microM) and GR73632 (0.1 microM), increased pial artery diameter. 3. In contrast, the selective NK2 receptor agonist, GR64349 (1 microM), produced a small vasoconstriction while the NK3 receptor-selective agonist, senktide (1 microM) was inactive. 4. Co-administration of GR82334 (1 microM), a selective NK1 receptor antagonist, inhibited the vasodilatation produced by SPOMe (0.1 microM) but not that caused by calcitonin gene-related peptide (CGRP, 0.01 microM). 5. The results are consistent with an involvement of NK1 receptors in the neurokinin-induced increase in guinea-pig pial artery diameter. PMID:7679026

Multiple-frame IR photo-recorder KIT-3M

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roos, E; Wilkins, P; Nebeker, N

2006-05-15

This paper reports the experimental results of a high-speed multi-frame infrared camera which has been developed in Sarov at VNIIEF. Earlier [1] we discussed the possibility of creation of the multi-frame infrared radiation photo-recorder with framing frequency about 1 MHz. The basis of the photo-recorder is a semiconductor ionization camera [2, 3], which converts IR radiation of spectral range 1-10 micrometers into a visible image. Several sequential thermal images are registered by using the IR converter in conjunction with a multi-frame electron-optical camera. In the present report we discuss the performance characteristics of a prototype commercial 9-frame high-speed IR photo-recorder.more » The image converter records infrared images of thermal fields corresponding to temperatures ranging from 300 C to 2000 C with an exposure time of 1-20 {micro}s at a frame frequency up to 500 KHz. The IR-photo-recorder camera is useful for recording the time evolution of thermal fields in fast processes such as gas dynamics, ballistics, pulsed welding, thermal processing, automotive industry, aircraft construction, in pulsed-power electric experiments, and for the measurement of spatial mode characteristics of IR-laser radiation.« less

Amino acid selective unlabeling for sequence specific resonance assignments in proteins

PubMed Central

Krishnarjuna, B.; Jaipuria, Garima; Thakur, Anushikha

2010-01-01

Sequence specific resonance assignment constitutes an important step towards high-resolution structure determination of proteins by NMR and is aided by selective identification and assignment of amino acid types. The traditional approach to selective labeling yields only the chemical shifts of the particular amino acid being selected and does not help in establishing a link between adjacent residues along the polypeptide chain, which is important for sequential assignments. An alternative approach is the method of amino acid selective ‘unlabeling’ or reverse labeling, which involves selective unlabeling of specific amino acid types against a uniformly 13C/15N labeled background. Based on this method, we present a novel approach for sequential assignments in proteins. The method involves a new NMR experiment named, {12COi–15Ni+1}-filtered HSQC, which aids in linking the 1HN/15N resonances of the selectively unlabeled residue, i, and its C-terminal neighbor, i + 1, in HN-detected double and triple resonance spectra. This leads to the assignment of a tri-peptide segment from the knowledge of the amino acid types of residues: i − 1, i and i + 1, thereby speeding up the sequential assignment process. The method has the advantage of being relatively inexpensive, applicable to 2H labeled protein and can be coupled with cell-free synthesis and/or automated assignment approaches. A detailed survey involving unlabeling of different amino acid types individually or in pairs reveals that the proposed approach is also robust to misincorporation of 14N at undesired sites. Taken together, this study represents the first application of selective unlabeling for sequence specific resonance assignments and opens up new avenues to using this methodology in protein structural studies. Electronic supplementary material The online version of this article (doi:10.1007/s10858-010-9459-z) contains supplementary material, which is available to authorized users. PMID:21153044

Evolution of a double amino acid substitution in the 5-enolpyruvylshikimate-3-phosphate synthase in Eleusine indica conferring high-level glyphosate resistance.

PubMed

Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R Douglas; Powles, Stephen B

2015-04-01

Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I+P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. © 2015 American Society of Plant Biologists. All Rights Reserved.

Evolution of a Double Amino Acid Substitution in the 5-Enolpyruvylshikimate-3-Phosphate Synthase in Eleusine indica Conferring High-Level Glyphosate Resistance1

PubMed Central

Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R. Douglas; Powles, Stephen B.

2015-01-01

Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I + P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. PMID:25717039

Triggered and catalyzed self-assembly of hyperbranched DNA structures for logic operations and homogeneous CRET biosensing of microRNA.

PubMed

Bi, Sai; Yue, Shuzhen; Wu, Qiang; Ye, Jiayan

2016-04-07

Toehold-mediated strand displacement-based nanocircuits are developed by integrating catalytic hairpin assembly (CHA) with hybridization chain reaction (HCR), which achieves self-assembly of hyperbranched DNA structures and is readily utilized as an enzyme-free amplifier for homogeneous CRET detection of microRNA with high sensitivity and selectivity.

A cardiovascular drug rescues mice from lethal sepsis by selectively attenuating a late-acting proinflammatory mediator, high mobility group box 1.

PubMed

Li, Wei; Li, Jianhua; Ashok, Mala; Wu, Rongqian; Chen, Dazhi; Yang, Lihong; Yang, Huan; Tracey, Kevin J; Wang, Ping; Sama, Andrew E; Wang, Haichao

2007-03-15

The pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., TNF, IL-1, and IFN-gamma) and late (e.g., high mobility group box 1 (HMGB1) protein) proinflammatory cytokines. The recent discovery of HMGB1 as a late mediator of lethal sepsis has prompted investigation for development of new experimental therapeutics. We found that many steroidal drugs (such as dexamethasone and cortisone) and nonsteroidal anti-inflammatory drugs (such as aspirin, ibuprofen, and indomethacin) failed to influence endotoxin-induced HMGB1 release even at superpharmacological concentrations (up to 10-25 microM). However, several steroid-like pigments (tanshinone I, tanshinone IIA, and cryptotanshinone) of a popular Chinese herb, Danshen (Salvia miltiorrhiza), dose dependently attenuated endotoxin-induced HMGB1 release in macrophage/monocyte cultures. A water-soluble tanshinone IIA sodium sulfonate derivative (TSNIIA-SS), which has been widely used as a Chinese medicine for patients with cardiovascular disorders, selectively abrogated endotoxin-induced HMGB1 cytoplasmic translocation and release in a glucocorticoid receptor-independent manner. Administration of TSNIIA-SS significantly protected mice against lethal endotoxemia and rescued mice from lethal sepsis even when the first dose was given 24 h after the onset of sepsis. The therapeutic effects were partly attributable to attenuation of systemic accumulation of HMGB1 (but not TNF and NO) and improvement of cardiovascular physiologic parameters (e.g., decrease in total peripheral vascular resistance and increase in cardiac stroke volume) in septic animals. Taken together, these data re-enforce the pathogenic role of HMGB1 in lethal sepsis, and support a therapeutic potential for TSNIIA-SS in the treatment of human sepsis.

Enactment of Teacher Identity in Resolving Student Disagreements in Small Group Peer Interactions

ERIC Educational Resources Information Center

Sharma, Bal Krishna

2013-01-01

This study presents a sequential analysis of the enactment of teacher identity in closing disagreements among students in small group peer interactions in an advanced academic writing class. In doing so, it discusses: (a) the micro-details of how oppositional stances and opinions are constructed, challenged and/or defended; (b) the sequential…

The Laser MicroJet (LMJ): a multi-solution technology for high quality micro-machining

NASA Astrophysics Data System (ADS)

Mai, Tuan Anh; Richerzhagen, Bernold; Snowdon, Paul C.; Wood, David; Maropoulos, Paul G.

2007-02-01

The field of laser micromachining is highly diverse. There are many different types of lasers available in the market. Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for different applications depending on material and feature size [1]. The main issues by using these lasers are heat damages, contamination and low ablation rates. This report examines on the application of the Laser MicroJet(R) (LMJ), a unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers, steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm (green) were employed for the micro-machining of these materials.

Resonant optical transducers for in-situ gas detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bond, Tiziana C.; Cole, Garrett; Goddard, Lynford

Configurations for in-situ gas detection are provided, and include miniaturized photonic devices, low-optical-loss, guided-wave structures and state-selective adsorption coatings. High quality factor semiconductor resonators have been demonstrated in different configurations, such as micro-disks, micro-rings, micro-toroids, and photonic crystals with the properties of very narrow NIR transmission bands and sensitivity up to 10.sup.-9 (change in complex refractive index). The devices are therefore highly sensitive to changes in optical properties to the device parameters and can be tunable to the absorption of the chemical species of interest. Appropriate coatings applied to the device enhance state-specific molecular detection.

Resonant optical transducers for in-situ gas detection

DOEpatents

Bond, Tiziana C; Cole, Garrett; Goddard, Lynford

2016-06-28

Configurations for in-situ gas detection are provided, and include miniaturized photonic devices, low-optical-loss, guided-wave structures and state-selective adsorption coatings. High quality factor semiconductor resonators have been demonstrated in different configurations, such as micro-disks, micro-rings, micro-toroids, and photonic crystals with the properties of very narrow NIR transmission bands and sensitivity up to 10.sup.-9 (change in complex refractive index). The devices are therefore highly sensitive to changes in optical properties to the device parameters and can be tunable to the absorption of the chemical species of interest. Appropriate coatings applied to the device enhance state-specific molecular detection.

Adrenal vein sampling in primary aldosteronism: concordance of simultaneous vs sequential sampling.

PubMed

Almarzooqi, Mohamed-Karji; Chagnon, Miguel; Soulez, Gilles; Giroux, Marie-France; Gilbert, Patrick; Oliva, Vincent L; Perreault, Pierre; Bouchard, Louis; Bourdeau, Isabelle; Lacroix, André; Therasse, Eric

2017-02-01

Many investigators believe that basal adrenal venous sampling (AVS) should be done simultaneously, whereas others opt for sequential AVS for simplicity and reduced cost. This study aimed to evaluate the concordance of sequential and simultaneous AVS methods. Between 1989 and 2015, bilateral simultaneous sets of basal AVS were obtained twice within 5 min, in 188 consecutive patients (59 women and 129 men; mean age: 53.4 years). Selectivity was defined by adrenal-to-peripheral cortisol ratio ≥2, and lateralization was defined as an adrenal aldosterone-to-cortisol ratio ≥2, the contralateral side. Sequential AVS was simulated using right sampling at -5 min (t = -5) and left sampling at 0 min (t = 0). There was no significant difference in mean selectivity ratio (P = 0.12 and P = 0.42 for the right and left sides respectively) and in mean lateralization ratio (P = 0.93) between t = -5 and t = 0. Kappa for selectivity between 2 simultaneous AVS was 0.71 (95% CI: 0.60-0.82), whereas it was 0.84 (95% CI: 0.76-0.92) and 0.85 (95% CI: 0.77-0.93) between sequential and simultaneous AVS at respectively -5 min and at 0 min. Kappa for lateralization between 2 simultaneous AVS was 0.84 (95% CI: 0.75-0.93), whereas it was 0.86 (95% CI: 0.78-0.94) and 0.80 (95% CI: 0.71-0.90) between sequential AVS and simultaneous AVS at respectively -5 min at 0 min. Concordance between simultaneous and sequential AVS was not different than that between 2 repeated simultaneous AVS in the same patient. Therefore, a better diagnostic performance is not a good argument to select the AVS method. © 2017 European Society of Endocrinology.

Sequentially Programmable and Cellularly Selective Assembly of Fluorescent Polymerized Vesicles for Monitoring Cell Apoptosis

PubMed Central

Peng, Shu; Pan, Yu‐Chen; Wang, Yaling; Xu, Zhe; Chen, Chao

2017-01-01

Abstract The introduction of controlled self‐assembly into living organisms opens up desired biomedical applications in wide areas including bioimaging/assays, drug delivery, and tissue engineering. Besides the enzyme‐activated examples reported before, controlled self‐assembly under integrated stimuli, especially in the form of sequential input, is unprecedented and ultimately challenging. This study reports a programmable self‐assembling strategy in living cells under sequentially integrated control of both endogenous and exogenous stimuli. Fluorescent polymerized vesicles are constructed by using cholinesterase conversion followed by photopolymerization and thermochromism. Furthermore, as a proof‐of‐principle application, the cell apoptosis involved in the overexpression of cholinesterase in virtue of the generated fluorescence is monitored, showing potential in screening apoptosis‐inducing drugs. The approach exhibits multiple advantages for bioimaging in living cells, including specificity to cholinesterase, red emission, wash free, high signal‐to‐noise ratio. PMID:29201625

Sequentially Programmable and Cellularly Selective Assembly of Fluorescent Polymerized Vesicles for Monitoring Cell Apoptosis.

PubMed

Peng, Shu; Pan, Yu-Chen; Wang, Yaling; Xu, Zhe; Chen, Chao; Ding, Dan; Wang, Yongjian; Guo, Dong-Sheng

2017-11-01

The introduction of controlled self-assembly into living organisms opens up desired biomedical applications in wide areas including bioimaging/assays, drug delivery, and tissue engineering. Besides the enzyme-activated examples reported before, controlled self-assembly under integrated stimuli, especially in the form of sequential input, is unprecedented and ultimately challenging. This study reports a programmable self-assembling strategy in living cells under sequentially integrated control of both endogenous and exogenous stimuli. Fluorescent polymerized vesicles are constructed by using cholinesterase conversion followed by photopolymerization and thermochromism. Furthermore, as a proof-of-principle application, the cell apoptosis involved in the overexpression of cholinesterase in virtue of the generated fluorescence is monitored, showing potential in screening apoptosis-inducing drugs. The approach exhibits multiple advantages for bioimaging in living cells, including specificity to cholinesterase, red emission, wash free, high signal-to-noise ratio.

Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde

NASA Astrophysics Data System (ADS)

Ding, Bin; Ma, Dian Xue; Zhang, Hui Min; Meng, Xin; Qiu, Rong Rong; Ren, Rong; Wu, Jie; Wu, Xiang Xia; Huo, Jian Zhong; Liu, Yuan Yuan; Shi, Xue Fang

2018-06-01

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(μ6-tp)1.5(μ2-Cl)(H2O) (DMF)2]·0.75H2O}n (H2tp = terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X = O, Cl) inorganic chains are linked via these full de-pronated tp2- ligands forming a unique 3D I1O2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu2+ over other cations with high quenching efficiency Ksv value 1.15 × 104 L·mol-1. As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu2+ and benzaldehyde.

Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde.

PubMed

Ding, Bin; Ma, Dian Xue; Zhang, Hui Min; Meng, Xin; Qiu, Rong Rong; Ren, Rong; Wu, Jie; Wu, Xiang Xia; Huo, Jian Zhong; Liu, Yuan Yuan; Shi, Xue Fang

2018-06-15

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(μ 6 -tp) 1.5 (μ 2 -Cl)(H 2 O) (DMF) 2 ]·0.75H 2 O} n (H 2 tp=terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X=O, Cl) inorganic chains are linked via these full de-pronated tp 2- ligands forming a unique 3D I 1 O 2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu 2+ over other cations with high quenching efficiency K sv value 1.15×10 4 L·mol -1 . As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu 2+ and benzaldehyde. Copyright © 2018 Elsevier B.V. All rights reserved.

High-speed micro-scale laser shock peening using a fiber laser (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhang, Chenfei; Deng, Leimin; Sun, Shiding; Lu, Yongfeng

2017-03-01

Laser shock peening using low-energy nanosecond (ns) fiber lasers was investigated in this study to realize high-speed micro-scale laser shock peening on selected positions without causing surface damage. Due to the employment of a fiber laser with high-frequency and prominent environmental adaptability, the laser peening system is able to work with a much higher speed compared to traditional peening systems using Nd:YAG lasers and is promising for in-situ applications in harsh environments. Detailed surface morphology investigations both on sacrificial coatings and Al alloy surfaces after the fiber laser peening revealed the effects of focal position, pulse duration, peak power density, and impact times. Micro-dent arrays were also obtained with different spot-to-spot distances. Obvious micro-hardness improvement was observed inside the laser-peening-induced microdents after the fiber laser shock peening.

Identification and biochemical characterization of small-molecule inhibitors of west nile virus serine protease by a high-throughput screen.

PubMed

Mueller, Niklaus H; Pattabiraman, Nagarajan; Ansarah-Sobrinho, Camilo; Viswanathan, Prasanth; Pierson, Theodore C; Padmanabhan, R

2008-09-01

West Nile virus and dengue virus are mosquito-borne flaviviruses that cause a large number of human infections each year. No vaccines or chemotherapeutics are currently available. These viruses encode a serine protease that is essential for polyprotein processing, a required step in the viral replication cycle. In this study, a high-throughput screening assay for the West Nile virus protease was employed to screen approximately 32,000 small-molecule compounds for identification of inhibitors. Lead inhibitor compounds with three distinct core chemical structures (1 to 3) were identified. In a secondary screening of selected compounds, two compounds, belonging to the 8-hydroxyquinoline family (compounds A and B) and containing core structure 1, were identified as potent inhibitors of the West Nile virus protease, with K(i) values of 3.2 +/- 0.3 microM and 3.4 +/- 0.6 microM, respectively. These compounds inhibited the dengue virus type 2 protease with K(i) values of 28.6 +/- 5.1 microM and 30.2 +/- 8.6 microM, respectively, showing some selectivity in the inhibition of these viral proteases. However, the compounds show no inhibition of cellular serine proteases, trypsin, or factor Xa. Kinetic analysis and molecular docking of compound B onto the known crystal structure of the West Nile virus protease indicate that the inhibitor binds in the substrate-binding cleft. Furthermore, compound B was capable of inhibiting West Nile virus RNA replication in cultured Vero cells (50% effective concentration, 1.4 +/- 0.4 microM; selectivity index, 100), presumably by inhibition of polyprotein processing.

An experimental analysis of process parameters to manufacture micro-channels in AISI H13 tempered steel by laser micro-milling

NASA Astrophysics Data System (ADS)

Teixidor, D.; Ferrer, I.; Ciurana, J.

2012-04-01

This paper reports the characterization of laser machining (milling) process to manufacture micro-channels in order to understand the incidence of process parameters on the final features. Selection of process operational parameters is highly critical for successful laser micromachining. A set of designed experiments is carried out in a pulsed Nd:YAG laser system using AISI H13 hardened tool steel as work material. Several micro-channels have been manufactured as micro-mold cavities varying parameters such as scanning speed (SS), pulse intensity (PI) and pulse frequency (PF). Results are obtained by evaluating the dimensions and the surface finish of the micro-channel. The dimensions and shape of the micro-channels produced with laser-micro-milling process exhibit variations. In general the use of low scanning speeds increases the quality of the feature in both surface finishing and dimensional.

Studying neighborhood crime across different macro spatial scales: The case of robbery in 4 cities.

PubMed

Hipp, John R; Wo, James C; Kim, Young-An

2017-11-01

Whereas there is a burgeoning literature focusing on the spatial distribution of crime events across neighborhoods or micro-geographic units in a specific city, the present study expands this line of research by selecting four cities that vary across two macro-spatial dimensions: population in the micro-environment, and population in the broader macro-environment. We assess the relationship between measures constructed at different spatial scales and robbery rates in blocks in four cities: 1) San Francisco (high in micro- and macro-environment population); 2) Honolulu (high in micro- but low in macro-environment population); 3) Los Angeles (low in micro- but high in macro-environment population); 4) Sacramento (low in micro- and macro-environment population). Whereas the socio-demographic characteristics of residents further than ½ mile away do not impact robbery rates, the number of people up to 2.5 miles away are related to robbery rates, especially in the two cities with smaller micro-environment population, implying a larger spatial scale than is often considered. The results show that coefficient estimates differ somewhat more between cities differing in micro-environment population compared to those differing based on macro-environment population. It is therefore necessary to consider the broader macro-environment even when focusing on the level of crime across neighborhoods or micro-geographic units within an area. Copyright © 2017 Elsevier Inc. All rights reserved.

Fabrication of polymer micro-lens array with pneumatically diaphragm-driven drop-on-demand inkjet technology.

PubMed

Xie, Dan; Zhang, Honghai; Shu, Xiayun; Xiao, Junfeng

2012-07-02

The paper reports an effective method to fabricate micro-lens arrays with the ultraviolet-curable polymer, using an original pneumatically diaphragm-driven drop-on-demand inkjet system. An array of plano convex micro-lenses can be formed on the glass substrate due to surface tension and hydrophobic effect. The micro-lens arrays have uniform focusing function, smooth and real planar surface. The fabrication process showed good repeatability as well, fifty micro-lenses randomly selected form 9 × 9 miro-lens array with an average diameter of 333.28μm showed 1.1% variations. Also, the focal length, the surface roughness and optical property of the fabricated micro-lenses are measured, analyzed and proved satisfactory. The technique shows great potential for fabricating polymer micro-lens arrays with high flexibility, simple technological process and low production cost.

Online Sequential Projection Vector Machine with Adaptive Data Mean Update

PubMed Central

Chen, Lin; Jia, Ji-Ting; Zhang, Qiong; Deng, Wan-Yu; Wei, Wei

2016-01-01

We propose a simple online learning algorithm especial for high-dimensional data. The algorithm is referred to as online sequential projection vector machine (OSPVM) which derives from projection vector machine and can learn from data in one-by-one or chunk-by-chunk mode. In OSPVM, data centering, dimension reduction, and neural network training are integrated seamlessly. In particular, the model parameters including (1) the projection vectors for dimension reduction, (2) the input weights, biases, and output weights, and (3) the number of hidden nodes can be updated simultaneously. Moreover, only one parameter, the number of hidden nodes, needs to be determined manually, and this makes it easy for use in real applications. Performance comparison was made on various high-dimensional classification problems for OSPVM against other fast online algorithms including budgeted stochastic gradient descent (BSGD) approach, adaptive multihyperplane machine (AMM), primal estimated subgradient solver (Pegasos), online sequential extreme learning machine (OSELM), and SVD + OSELM (feature selection based on SVD is performed before OSELM). The results obtained demonstrated the superior generalization performance and efficiency of the OSPVM. PMID:27143958

Online Sequential Projection Vector Machine with Adaptive Data Mean Update.

PubMed

Chen, Lin; Jia, Ji-Ting; Zhang, Qiong; Deng, Wan-Yu; Wei, Wei

2016-01-01

We propose a simple online learning algorithm especial for high-dimensional data. The algorithm is referred to as online sequential projection vector machine (OSPVM) which derives from projection vector machine and can learn from data in one-by-one or chunk-by-chunk mode. In OSPVM, data centering, dimension reduction, and neural network training are integrated seamlessly. In particular, the model parameters including (1) the projection vectors for dimension reduction, (2) the input weights, biases, and output weights, and (3) the number of hidden nodes can be updated simultaneously. Moreover, only one parameter, the number of hidden nodes, needs to be determined manually, and this makes it easy for use in real applications. Performance comparison was made on various high-dimensional classification problems for OSPVM against other fast online algorithms including budgeted stochastic gradient descent (BSGD) approach, adaptive multihyperplane machine (AMM), primal estimated subgradient solver (Pegasos), online sequential extreme learning machine (OSELM), and SVD + OSELM (feature selection based on SVD is performed before OSELM). The results obtained demonstrated the superior generalization performance and efficiency of the OSPVM.

Digital Photonic Production of Micro Structures in Glass by In-Volume Selective Laser-Induced Etching using a High Speed Micro Scanner

NASA Astrophysics Data System (ADS)

Gottmann, Jens; Hermans, Martin; Ortmann, Jürgen

Digital photonic production of 3D microfluidic devices and assembled micro mechanics inside fused silica glass is carried out using ISLE directly from digital CAD data. To exploit the potential productivity of new high average power fs-lasers >150 W a modular high speed scanning system has been developed. Acousto-optical beam deflection, galvo-scanners and translation stages are controlled by CAM software. Using a lens with 10 mm focal length a focus radius of 1 μm is scanned with a velocity of 12 m/s on 400 μm track radius enabling the up-scaling of the ISLE- process using fs-laser radiation with up to 30 W.

A simple fluorescent probe for the fast sequential detection of copper and biothiols based on a benzothiazole derivative

NASA Astrophysics Data System (ADS)

Shen, Youming; Zhang, Xiangyang; Zhang, Chunxiang; Zhang, Youyu; Jin, Junling; Li, Haitao

2018-02-01

A simple benzothiazole fluorescent chemosensor was developed for the fast sequential detection of Cu2 + and biothiols through modulating the excited-state intramolecular proton transfer (ESIPT) process. The compound 1 exhibits highly selective and sensitive fluorescence ;on-off; recognition to Cu2 + with a 1:1 binding stoichiometry by ESIPT hinder. The in situ generated 1-Cu2 + complex can serve as an ;on-off; fluorescent probe for high selectivity toward biothiols via Cu2 + displacement approach, which exerts ESIPT recovery. It is worth pointing out that the 1-Cu2 + complex shows faster for cysteins (within 1 min) than other biothiols such as homocysteine (25 min) and glutathione (25 min). Moreover, the compound 1 displays 160 nm Stoke-shift for reversibly monitoring Cu2 + and biothiols. In addition, the probe is successfully used for fluorescent cellular imaging. This strategy via modulation the ESIPT state has been used for determination of Cu2 + and Cys with satisfactory results, which further demonstrates its value of practical applications.

High resolution laser micro sintering / melting using q-switched and high brilliant laser radiation

NASA Astrophysics Data System (ADS)

Exner, H.; Streek, A.

2015-03-01

Since the discovery of selective laser sintering/melting, numerous modifications have been made to upgrade or customize this technology for industrial purposes. Laser micro sintering (LMS) is one of those modifications: Powders with particles in the range of a few micrometers are used to obtain products with highly resolved structures. Pulses of a q-switched laser had been considered necessary in order to generate sinter layers from the micrometer scaled metal powders. LMS has been applied with powders from metals as well as from ceramic and cermet feedstock's to generate micro parts. Recent technological progress and the application of high brilliant continuous laser radiation have now allowed an efficient laser sintering/melting of micrometer scaled metal powders. Thereby it is remarkable that thin sinter layers are generated using high continuous laser power. The principles of the process, the state of the art in LMS concerning its advantages and limitations and furthermore the latest results of the recent development of this technology will be presented. Laser Micro Sintering / Laser Micro Melting (LMM) offer a vision for a new dimension of additive fabrication of miniature and precise parts also with application potential in all engineering fields.

A comparison of sequential and spiral scanning techniques in brain CT.

PubMed

Pace, Ivana; Zarb, Francis

2015-01-01

To evaluate and compare image quality and radiation dose of sequential computed tomography (CT) examinations of the brain and spiral CT examinations of the brain imaged on a GE HiSpeed NX/I Dual Slice 2CT scanner. A random sample of 40 patients referred for CT examination of the brain was selected and divided into 2 groups. Half of the patients were scanned using the sequential technique; the other half were scanned using the spiral technique. Radiation dose data—both the computed tomography dose index (CTDI) and the dose length product (DLP)—were recorded on a checklist at the end of each examination. Using the European Guidelines on Quality Criteria for Computed Tomography, 4 radiologists conducted a visual grading analysis and rated the level of visibility of 6 anatomical structures considered necessary to produce images of high quality. The mean CTDI(vol) and DLP values were statistically significantly higher (P <.05) with the sequential scans (CTDI(vol): 22.06 mGy; DLP: 304.60 mGy • cm) than with the spiral scans (CTDI(vol): 14.94 mGy; DLP: 229.10 mGy • cm). The mean image quality rating scores for all criteria of the sequential scanning technique were statistically significantly higher (P <.05) in the visual grading analysis than those of the spiral scanning technique. In this local study, the sequential technique was preferred over the spiral technique for both overall image quality and differentiation between gray and white matter in brain CT scans. Other similar studies counter this finding. The radiation dose seen with the sequential CT scanning technique was significantly higher than that seen with the spiral CT scanning technique. However, image quality with the sequential technique was statistically significantly superior (P <.05).

Microengineering of magnetic bearings and actuators

NASA Astrophysics Data System (ADS)

Ghantasala, Muralihar K.; Qin, LiJiang; Sood, Dinesh K.; Zmood, Ronald B.

2000-06-01

Microengineering has evolved in the last decade as a subject of its own with the current research encompassing every possible area of devices from electromagnetic to optical and bio-micro electromechanical systems (MEMS). The primary advantage of the micro system technology is its small size, potential to produce high volume and low cost devices. However, the major impediments in the successful realization of many micro devices in practice are the reliability, packaging and integration with the existing microelectronics technology. Microengineering of actuators has recently grown tremendously due to its possible applicability to a wide range of devices of practical importance and the availability of a choice of materials. Selection of materials has been one of the important aspects of the design and fabrication of many micro system and actuators. This paper discusses the issues related to the selection of materials and subsequently their effect on the performance of the actuator. These will be discussed taking micro magnetic actuators and bearings, in particular, as examples. Fabrication and processing strategies and performance evaluation methods adopted will be described. Current status of the technology and projected futuristic applications in this area will be reviewed.

A Manganin Thin Film Ultra-High Pressure Sensor for Microscale Detonation Pressure Measurement

PubMed Central

Zhang, Guodong; Zhao, Yulong; Zhao, Yun; Wang, Xinchen; Ren, Wei; Li, Hui; Zhao, You

2018-01-01

With the development of energetic materials (EMs) and microelectromechanical systems (MEMS) initiating explosive devices, the measurement of detonation pressure generated by EMs in the microscale has become a pressing need. This paper develops a manganin thin film ultra-high pressure sensor based on MEMS technology for measuring the output pressure from micro-detonator. A reliable coefficient is proposed for designing the sensor’s sensitive element better. The sensor employs sandwich structure: the substrate uses a 0.5 mm thick alumina ceramic, the manganin sensitive element with a size of 0.2 mm × 0.1 mm × 2 μm and copper electrodes of 2 μm thick are sputtered sequentially on the substrate, and a 25 μm thick insulating layer of polyimide is wrapped on the sensitive element. The static test shows that the piezoresistive coefficient of manganin thin film is 0.0125 GPa−1. The dynamic experiment indicates that the detonation pressure of micro-detonator is 12.66 GPa, and the response time of the sensor is 37 ns. In a word, the sensor developed in this study is suitable for measuring ultra-high pressure in microscale and has a shorter response time than that of foil-like manganin gauges. Simultaneously, this study could be beneficial to research on ultra-high-pressure sensors with smaller size. PMID:29494519

Quasi-distributed and wavelength selective addressing of optical micro-resonators based on long period fiber gratings.

PubMed

Farnesi, D; Chiavaioli, F; Baldini, F; Righini, G C; Soria, S; Trono, C; Conti, G Nunzi

2015-08-10

A novel all-in-fiber method for coupling light to high-Q silica whispering gallery mode (WGM) optical micro-resonators is presented, which is based on a pair of long period fiber gratings (LPGs) written in the same silica fiber, along with a thick fiber taper (15-18 μm in waist) in between the LPGs. The proposed coupling structure is robust and can be replicated many times along the same fiber simply cascading LPGs with different bands. Typical Q-factors of the order of 10(8) and total coupling efficiency up to 60% were measured collecting the resonances of microspheres or microbubbles at the fiber end. This approach uniquely allows quasi-distributed and wavelength selective addressing of different micro-resonators along the same fiber.

Growth of potassium niobate micro-hexagonal tablets with monoclinic phase and its excellent piezoelectric property

NASA Astrophysics Data System (ADS)

Chen, Zhong; Huang, Jingyun; Wang, Ye; Yang, Yefeng; Wu, Yongjun; Ye, Zhizhen

2012-09-01

Potassium niobate micro-hexagonal tablets were synthesized through hydrothermal reaction with KOH, H2O and Nb2O5 as source materials by using a polycrystalline Al2O3 as substrate. X-ray diffraction, Raman spectra and selected area electron diffraction analysis results indicated that the tablets exhibit monoclinic phase structure and are highly crystallized. Meanwhile, piezoelectric property of the micro-hexagonal tablets was investigated. The as-synthesized tablets exhibit excellent piezoactivities in the experiments, and an effective piezoelectric coefficient of around 80 pm/V was obtained. The tablets have huge potential applications in micro/nano-integrated piezoelectric and optical devices.

Design of the micro pressure multi-node measuring system for micro-fluidic chip

NASA Astrophysics Data System (ADS)

Mu, Lili; Guo, Shuheng; Rong, Li; Yin, Ke

2016-01-01

An online multi-node microfludic pressure measuring system was designed in the paper. The research focused on the design of pressure test circuit system and methods on dealing with pressure data collecting. The MPXV7002 micro-pressure sensor was selected to measure the chip inside channel pressure and installed by a silicone tube on different micro-channel measured nodes. The pressure transmission loss was estimated in the paper, and corrected by the filtering and smoothing method. The pressure test experiment was carried out and the data were analyzed. Finally, the measuring system was calibrated. The results showed that the measuring system had high testing precision.

Nutrient Recovery from the Dry Grind Process Using Sequential Micro and Ultrafiltration of Thin Stillage

USDA-ARS?s Scientific Manuscript database

The effectiveness of microfiltration (MF) and ultrafiltration (UF) for nutrient recovery from a thin stillage stream was determined. When a stainless steel MF membrane (0.1 um pore size) was used, the content of solids increased from 7.0% to 22.8% with a mean permeate flux rate of 45 L/m**2/h (LMH)...

Sequential nitric oxide measurements during the emergency department treatment of acute vasoocclusive sickle cell crisis.

PubMed

Lopez, B L; Davis-Moon, L; Ballas, S K; Ma, X L

2000-05-01

This prospective study was designed to examine the relationship between serial serum nitric oxide (NO) levels and pain during the emergency department (ED) treatment of acute vasoocclusive sickle cell crisis (SCC). 102 patient visits, age > or =18 years of age, presenting to the ED with uncomplicated, typical SCC pain had serum NO levels obtained at 2-hr intervals during treatment of pain and were measured using an NO-specific chemiluminesence technique. Pain was measured prior to each NO measurement using a 10 cm visual analog scale (VAS), and subjects were divided into a persistent pain group and an improved pain group. Patients with persistent pain had significantly low initial NO levels (11.51 microM +/- 2.8, P < 0.05) while those with pain improvement had higher initial NO levels (18.1 microM +/- 3.08, P < 0.05). There was no significant correlation between changes in NO and changes in pain scores. These results suggest that the initial NO level may serve as a marker for the severity of tissue ischemia. Sequential NO levels do not appear useful in predicting the course of SCC.

Estimation of free carrier concentrations in high-quality heavily doped GaN:Si micro-rods by photoluminescence and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Mohajerani, M. S.; Khachadorian, S.; Nenstiel, C.; Schimpke, T.; Avramescu, A.; Strassburg, M.; Hoffmann, A.; Waag, A.

2016-03-01

The controlled growth of highly n-doped GaN micro rods is one of the major challenges in the fabrication of recently developed three-dimensional (3D) core-shell light emitting diodes (LEDs). In such structures with a large active area, higher electrical conductivity is needed to achieve higher current density. In this contribution, we introduce high quality heavily-doped GaN:Si micro-rods which are key elements of the newly developed 3D core-shell LEDs. These structures were grown by metal-organic vapor phase epitaxy (MOVPE) using selective area growth (SAG). We employed spatially resolved micro-Raman and micro-photoluminescence (PL) in order to directly determine a free-carrier concentration profile in individual GaN micro-rods. By Raman spectroscopy, we analyze the low-frequency branch of the longitudinal optical (LO)-phonon-plasmon coupled modes and estimate free carrier concentrations from ≍ 2.4 × 1019 cm-3 up to ≍ 1.5 × 1020 cm-3. Furthermore, free carrier concentrations are determined by estimating Fermi energy level from the near band edge emission measured by low-temperature PL. The results from both methods reveal a good consistency.

Design and fabrication of embedded micro-mirror inserts for out-of-plane coupling in PCB-level optical interconnections

NASA Astrophysics Data System (ADS)

Van Erps, Jurgen; Hendrickx, Nina; Bosman, Erwin; Van Daele, Peter; Debaes, Christof; Thienpont, Hugo

2010-05-01

Optical interconnections have gained interest over the last years, and several approaches have been presented for the integration of optics to the printed circuit board (PCB)-level. The use of a polymer optical waveguide layer appears to be the prevailing solution to route optical signals on the PCB. The most difficult issue is the efficient out-of-plane coupling of light between surface-normal optoelectronic devices (lasers and photodetectors) and PCB-integrated waveguides. The most common approach consists of using 45° reflecting micro-mirrors. The micro-mirror performance significantly affects the total insertion loss of the optical interconnect system, and hence has a crucial role on the system's bit error rate (BER) characteristics. Several technologies have been proposed for the fabrication of 45° reflector micro-mirrors directly into waveguides. Alternatively, it is possible to make use of discrete coupling components which have to be inserted into cavities formed in the PCB-integrated waveguides. In this paper, we present a hybrid approach where we try to combine the advantages of integrated and discrete coupling mirrors, i.e. low coupling loss and maintenance of the planararity of the top surface of the optical layer, allowing the lamination of additional layers or the mounting of optoelectronic devices. The micro-mirror inserts are designed through non-sequential ray tracing simulations, including a tolerance analysis, and subsequently prototyped with Deep Proton Writing (DPW). The DPW prototypes are compatible with mass fabrication at low cost in a wide variety of high-tech plastics. The DPW micro-mirror insert is metallized and inserted in a laser ablated cavity in the optical layer and in a next step covered with cladding material. Surface roughness measurements confirm the excellent quality of the mirror facet. An average mirror loss of 0.35-dB was measured in a receiver scheme, which is the most stringent configuration. Finally, the configuration is robust, since the mirror is embedded and thus protected from environmental contamination, like dust or moisture adsorption, which makes them interesting candidates for out-of-plane coupling in high-end boards.

Anticipating conflict facilitates controlled stimulus-response selection

PubMed Central

Correa, Ángel; Rao, Anling; Nobre, Anna C.

2014-01-01

Cognitive control can be triggered in reaction to previous conflict, as suggested by the finding of sequential effects in conflict tasks. Can control also be triggered proactively by presenting cues predicting conflict (‘proactive control’)? We exploited the high temporal resolution of event-related potentials (ERPs) and controlled for sequential effects to ask whether proactive control based on anticipating conflict modulates neural activity related to cognitive control, as may be predicted from the conflict-monitoring model. ERPs associated with conflict detection (N2) were measured during a cued flanker task. Symbolic cues were either informative or neutral with respect to whether the target involved conflicting or congruent responses. Sequential effects were controlled by analysing the congruency of the previous trial. The results showed that cuing conflict facilitated conflict resolution and reduced the N2 latency. Other potentials (frontal N1 and P3) were also modulated by cuing conflict. Cuing effects were most evident after congruent than after incongruent trials. This interaction between cuing and sequential effects suggests neural overlap between the control networks triggered by proactive and reactive signals. This finding clarifies why previous neuroimaging studies, in which reactive sequential effects were not controlled, have rarely found anticipatory effects upon conflict-related activity. Finally, the high temporal resolution of ERPs was critical to reveal a temporal modulation of conflict detection by proactive control. This novel finding suggests that anticipating conflict speeds up conflict detection and resolution. Recent research suggests that this anticipatory mechanism may be mediated by pre-activation of the ACC during the preparatory interval. PMID:18823248

Comparative MicroRNA Expression Patterns in Fibroblasts after Low and High Doses of Low-LET Radiation Exposure

NASA Technical Reports Server (NTRS)

Maes, Olivier C.; Xu, Suying; Hada, Megumi; Wu, Honglu; Wang, Eugenia

2007-01-01

Exposure to ionizing radiation causes DNA damage to cells, and provokes a plethora of cellular responses controlled by unique gene-directed signaling pathways. MicroRNAs (miRNAs) are small (22-nucleotide), non-coding RNAs which functionally silence gene expression by either degrading the messages or inhibiting translation. Here we investigate radiation-dependent changes in these negative regulators by comparing the expression patterns of all 462 known human miRNAs in fibroblasts, after exposure to low (0.1 Gy) or high (2 Gy) doses of X-rays at 30 min, 2, 6 and 24 hrs post-treatment. The expression patterns of microRNAs after low and high doses of radiation show a similar qualitative down-regulation trend at early (0.5 hr) and late (24 hr) time points, with a quantitatively steeper slope following the 2 Gy exposures. Interestingly, an interruption of this downward trend is observed after the 2 Gy exposure, i.e. a significant up-regulation of microRNAs at 2 hrs, then reverting to the downward trend by 6 hrs; this interruption at the intermediate time point was not observed with the 0.1 Gy exposure. At the early time point (0.5 hr), candidate gene targets of selected down-regulated microRNAs, common to both 0.1 and 2 Gy exposures, were those functioning in chromatin remodeling. Candidate target genes of unique up-regulated microRNAs seen at a 2 hr intermediate time point, after the 2 Gy exposure only, are those involved in cell death signaling. Finally, putative target genes of down-regulated microRNAs seen at the late (24 hr) time point after either doses of radiation are those involved in the up-regulation of DNA repair, cell signaling and homeostasis. Thus we hypothesize that after radiation exposure, microRNAs acting as hub negative regulators for unique signaling pathways needed to be down-regulated so as to de-repress their target genes for the proper cellular responses, including DNA repair and cell maintenance. The unique microRNAs up-regulated at 2 hr after 2 Gy suggest the cellular response to functionally suppress the apoptotic death signaling reflex after exposure to high dose radiation. Further analyses with transcriptome and global proteomic profiling will validate the reciprocal expression of signature microRNAs selected in our radiation-exposed cells, and their candidate target gene families, and test our hypothesis that unique radiation-specific microRNAs are keys in governing signaling responses for damage control of this environmental hazard.

Biocatalytic synthesis of 4-pregnen-20,21-diol-3-one, a selective inhibitor of human 5alpha-reductase type II.

PubMed

Hannemann, Frank; Bernhardt, Rita; Jose, Joachim

2007-10-01

Biocatalysis, the conversion of substrates into valuable products by the use of enzymes, has some striking advantages in comparison to standard organic chemistry for drug synthesis. By biocatalysis, substrates that contain several identical reactive groups at different positions can be converted with high regio-selectivity and enantio-selectivity. In this study, an E. coli isolate (E132) was identified which was able to convert the steroid desoxycorticosterone into the product 4-pregnen-20,21-diol-3-one in real terms. The product was purified from the cell culture supernatant by HPLC and its structure was demonstrated by mass spectrometry and NMR spectroscopy. It was tested on inhibition of human 5alpha-reductases type I and type II. At a concentration of 10 microM, inhibition was 49.0% for type I and 81.8% for type II, whereas there was no inhibition of human aromatase (CYP19) at 20 microM and human 17alpha-hydroxylase-C17,20-lyase (CYP17) at 2.5 microM detectable. The IC50 value of 4-pregnen-20,21-diol-3-one for human 5alpha-reductase type II was determined to be 1.56 microM.

In-Situ Measurement of High-Temperature Proton Exchange Membrane Fuel Cell Stack Using Flexible Five-in-One Micro-Sensor

PubMed Central

Lee, Chi-Yuan; Weng, Fang-Bor; Kuo, Yzu-Wei; Tsai, Chao-Hsuan; Cheng, Yen-Ting; Cheng, Chih-Kai; Lin, Jyun-Ting

2016-01-01

In the chemical reaction that proceeds in a high-temperature proton exchange membrane fuel cell stack (HT-PEMFC stack), the internal local temperature, voltage, pressure, flow and current nonuniformity may cause poor membrane material durability and nonuniform fuel distribution, thus influencing the performance and lifetime of the fuel cell stack. In this paper micro-electro-mechanical systems (MEMS) are utilized to develop a high-temperature electrochemical environment-resistant five-in-one micro-sensor embedded in the cathode channel plate of an HT-PEMFC stack, and materials and process parameters are appropriately selected to protect the micro-sensor against failure or destruction during long-term operation. In-situ measurement of the local temperature, voltage, pressure, flow and current distributions in the HT-PEMFC stack is carried out. This integrated micro-sensor has five functions, and is favorably characterized by small size, good acid resistance and temperature resistance, quick response, real-time measurement, and the goal is being able to be put in any place for measurement without affecting the performance of the battery. PMID:27763559

In-Situ Measurement of High-Temperature Proton Exchange Membrane Fuel Cell Stack Using Flexible Five-in-One Micro-Sensor.

PubMed

Lee, Chi-Yuan; Weng, Fang-Bor; Kuo, Yzu-Wei; Tsai, Chao-Hsuan; Cheng, Yen-Ting; Cheng, Chih-Kai; Lin, Jyun-Ting

2016-10-18

In the chemical reaction that proceeds in a high-temperature proton exchange membrane fuel cell stack (HT-PEMFC stack), the internal local temperature, voltage, pressure, flow and current nonuniformity may cause poor membrane material durability and nonuniform fuel distribution, thus influencing the performance and lifetime of the fuel cell stack. In this paper micro-electro-mechanical systems (MEMS) are utilized to develop a high-temperature electrochemical environment-resistant five-in-one micro-sensor embedded in the cathode channel plate of an HT-PEMFC stack, and materials and process parameters are appropriately selected to protect the micro-sensor against failure or destruction during long-term operation. In-situ measurement of the local temperature, voltage, pressure, flow and current distributions in the HT-PEMFC stack is carried out. This integrated micro-sensor has five functions, and is favorably characterized by small size, good acid resistance and temperature resistance, quick response, real-time measurement, and the goal is being able to be put in any place for measurement without affecting the performance of the battery.

Predictive Surface Roughness Model for End Milling of Machinable Glass Ceramic

NASA Astrophysics Data System (ADS)

Mohan Reddy, M.; Gorin, Alexander; Abou-El-Hossein, K. A.

2011-02-01

Advanced ceramics of Machinable glass ceramic is attractive material to produce high accuracy miniaturized components for many applications in various industries such as aerospace, electronics, biomedical, automotive and environmental communications due to their wear resistance, high hardness, high compressive strength, good corrosion resistance and excellent high temperature properties. Many research works have been conducted in the last few years to investigate the performance of different machining operations when processing various advanced ceramics. Micro end-milling is one of the machining methods to meet the demand of micro parts. Selecting proper machining parameters are important to obtain good surface finish during machining of Machinable glass ceramic. Therefore, this paper describes the development of predictive model for the surface roughness of Machinable glass ceramic in terms of speed, feed rate by using micro end-milling operation.

Multiple independent identification decisions: a method of calibrating eyewitness identifications.

PubMed

Pryke, Sean; Lindsay, R C L; Dysart, Jennifer E; Dupuis, Paul

2004-02-01

Two experiments (N = 147 and N = 90) explored the use of multiple independent lineups to identify a target seen live. In Experiment 1, simultaneous face, body, and sequential voice lineups were used. In Experiment 2, sequential face, body, voice, and clothing lineups were used. Both studies demonstrated that multiple identifications (by the same witness) from independent lineups of different features are highly diagnostic of suspect guilt (G. L. Wells & R. C. L. Lindsay, 1980). The number of suspect and foil selections from multiple independent lineups provides a powerful method of calibrating the accuracy of eyewitness identification. Implications for use of current methods are discussed. ((c) 2004 APA, all rights reserved)

A sampling and classification item selection approach with content balancing.

PubMed

Chen, Pei-Hua

2015-03-01

Existing automated test assembly methods typically employ constrained combinatorial optimization. Constructing forms sequentially based on an optimization approach usually results in unparallel forms and requires heuristic modifications. Methods based on a random search approach have the major advantage of producing parallel forms sequentially without further adjustment. This study incorporated a flexible content-balancing element into the statistical perspective item selection method of the cell-only method (Chen et al. in Educational and Psychological Measurement, 72(6), 933-953, 2012). The new method was compared with a sequential interitem distance weighted deviation model (IID WDM) (Swanson & Stocking in Applied Psychological Measurement, 17(2), 151-166, 1993), a simultaneous IID WDM, and a big-shadow-test mixed integer programming (BST MIP) method to construct multiple parallel forms based on matching a reference form item-by-item. The results showed that the cell-only method with content balancing and the sequential and simultaneous versions of IID WDM yielded results comparable to those obtained using the BST MIP method. The cell-only method with content balancing is computationally less intensive than the sequential and simultaneous versions of IID WDM.

CLAss-Specific Subspace Kernel Representations and Adaptive Margin Slack Minimization for Large Scale Classification.

PubMed

Yu, Yinan; Diamantaras, Konstantinos I; McKelvey, Tomas; Kung, Sun-Yuan

2018-02-01

In kernel-based classification models, given limited computational power and storage capacity, operations over the full kernel matrix becomes prohibitive. In this paper, we propose a new supervised learning framework using kernel models for sequential data processing. The framework is based on two components that both aim at enhancing the classification capability with a subset selection scheme. The first part is a subspace projection technique in the reproducing kernel Hilbert space using a CLAss-specific Subspace Kernel representation for kernel approximation. In the second part, we propose a novel structural risk minimization algorithm called the adaptive margin slack minimization to iteratively improve the classification accuracy by an adaptive data selection. We motivate each part separately, and then integrate them into learning frameworks for large scale data. We propose two such frameworks: the memory efficient sequential processing for sequential data processing and the parallelized sequential processing for distributed computing with sequential data acquisition. We test our methods on several benchmark data sets and compared with the state-of-the-art techniques to verify the validity of the proposed techniques.

Statistical estimation of femur micro-architecture using optimal shape and density predictors.

PubMed

Lekadir, Karim; Hazrati-Marangalou, Javad; Hoogendoorn, Corné; Taylor, Zeike; van Rietbergen, Bert; Frangi, Alejandro F

2015-02-26

The personalization of trabecular micro-architecture has been recently shown to be important in patient-specific biomechanical models of the femur. However, high-resolution in vivo imaging of bone micro-architecture using existing modalities is still infeasible in practice due to the associated acquisition times, costs, and X-ray radiation exposure. In this study, we describe a statistical approach for the prediction of the femur micro-architecture based on the more easily extracted subject-specific bone shape and mineral density information. To this end, a training sample of ex vivo micro-CT images is used to learn the existing statistical relationships within the low and high resolution image data. More specifically, optimal bone shape and mineral density features are selected based on their predictive power and used within a partial least square regression model to estimate the unknown trabecular micro-architecture within the anatomical models of new subjects. The experimental results demonstrate the accuracy of the proposed approach, with average errors of 0.07 for both the degree of anisotropy and tensor norms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bio-barcode gel assay for microRNA

NASA Astrophysics Data System (ADS)

Lee, Hyojin; Park, Jeong-Eun; Nam, Jwa-Min

2014-02-01

MicroRNA has been identified as a potential biomarker because expression level of microRNA is correlated with various cancers. Its detection at low concentrations would be highly beneficial for cancer diagnosis. Here, we develop a new type of a DNA-modified gold nanoparticle-based bio-barcode assay that uses a conventional gel electrophoresis platform and potassium cyanide chemistry and show this assay can detect microRNA at aM levels without enzymatic amplification. It is also shown that single-base-mismatched microRNA can be differentiated from perfectly matched microRNA and the multiplexed detection of various combinations of microRNA sequences is possible with this approach. Finally, differently expressed microRNA levels are selectively detected from cancer cells using the bio-barcode gel assay, and the results are compared with conventional polymerase chain reaction-based results. The method and results shown herein pave the way for practical use of a conventional gel electrophoresis for detecting biomolecules of interest even at aM level without polymerase chain reaction amplification.

Attention-Based Recurrent Temporal Restricted Boltzmann Machine for Radar High Resolution Range Profile Sequence Recognition.

PubMed

Zhang, Yifan; Gao, Xunzhang; Peng, Xuan; Ye, Jiaqi; Li, Xiang

2018-05-16

The High Resolution Range Profile (HRRP) recognition has attracted great concern in the field of Radar Automatic Target Recognition (RATR). However, traditional HRRP recognition methods failed to model high dimensional sequential data efficiently and have a poor anti-noise ability. To deal with these problems, a novel stochastic neural network model named Attention-based Recurrent Temporal Restricted Boltzmann Machine (ARTRBM) is proposed in this paper. RTRBM is utilized to extract discriminative features and the attention mechanism is adopted to select major features. RTRBM is efficient to model high dimensional HRRP sequences because it can extract the information of temporal and spatial correlation between adjacent HRRPs. The attention mechanism is used in sequential data recognition tasks including machine translation and relation classification, which makes the model pay more attention to the major features of recognition. Therefore, the combination of RTRBM and the attention mechanism makes our model effective for extracting more internal related features and choose the important parts of the extracted features. Additionally, the model performs well with the noise corrupted HRRP data. Experimental results on the Moving and Stationary Target Acquisition and Recognition (MSTAR) dataset show that our proposed model outperforms other traditional methods, which indicates that ARTRBM extracts, selects, and utilizes the correlation information between adjacent HRRPs effectively and is suitable for high dimensional data or noise corrupted data.

Determination of Strain Rate Sensitivity of Micro-struts Manufactured Using the Selective Laser Melting Method

NASA Astrophysics Data System (ADS)

Gümrük, Recep; Mines, R. A. W.; Karadeniz, Sami

2018-03-01

Micro-lattice structures manufactured using the selective laser melting (SLM) process provides the opportunity to realize optimal cellular materials for impact energy absorption. In this paper, strain rate-dependent material properties are measured for stainless steel 316L SLM micro-lattice struts in the strain rate range of 10-3 to 6000 s-1. At high strain rates, a novel version of the split Hopkinson Bar has been developed. Strain rate-dependent materials data have been used in Cowper-Symonds material model, and the scope and limit of this model in the context of SLM struts have been discussed. Strain rate material data and the Cowper-Symonds model have been applied to the finite element analysis of a micro-lattice block subjected to drop weight impact loading. The model output has been compared to experimental results, and it has been shown that the increase in crush stress due to impact loading is mainly the result of strain rate material behavior. Hence, a systematic methodology has been developed to investigate the impact energy absorption of a micro-lattice structure manufactured using additive layer manufacture (SLM). This methodology can be extended to other micro-lattice materials and configurations, and to other impact conditions.

Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column.

PubMed

Satínský, Dalibor; Huclová, Jitka; Ferreira, Raquel L C; Montenegro, Maria Conceição B S M; Solich, Petr

2006-02-13

The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection. A Chromolith SpeedROD RP-18e, 50-4.6 mm column with 10 mm precolumn and a FIAlab 3000 system with a six-port selection valve and 5 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-tetrahydrofuran-0.05M acetic acid (10:10:90, v/v/v), pH 3.75 adjusted with triethylamine, flow rate 0.48 mlmin(-1), UV-detection was at 245 nm. The analysis time was <11 min. A new SIC method was validated and compared with HPLC. The method was found to be useful for the routine analysis of the active compounds ambroxol and preservatives (methylparaben or benzoic acid) in various pharmaceutical syrups and drops.

The QUIET Instrument

NASA Technical Reports Server (NTRS)

Gaier, T.; Kangaslahti, P.; Lawrence, C. R.; Leitch, E. M.; Wollack, E. J.

2012-01-01

The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting the imprint of inflationary gravitational waves at large angular scales ( approx 1 deg.) . Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4 m side-fed Dragonian telescope. The polarimeters which form the focal planes use a highly compact design based on High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements of the Stokes parameters Q, U, and I in a single module. The 17-element Q-band polarimeter array, with a central frequency of 43.1 GHz, has the best sensitivity (69 micro Ks(exp 1/2)) and the lowest instrumental systematic errors ever achieved in this band, contributing to the tensor-to-scalar ratio at r < 0.1. The 84-element W-band polarimeter array has a sensitivity of 87 micro Ks(exp 1/2) at a central frequency of 94.5 GHz. It has the lowest systematic errors to date, contributing at r < 0.01 (QUIET Collaboration 2012) The two arrays together cover multipoles in the range l approximately equals 25-975 . These are the largest HEMT-ba.sed arrays deployed to date. This article describes the design, calibration, performance of, and sources of systematic error for the instrument,

Ultrasonic Micro-Blades for the Rapid Extraction of Impact Tracks from Aerogel

NASA Technical Reports Server (NTRS)

Ishii, H. A.; Graham, G. A.; Kearsley, A. T.; Grant, P. G.; Snead, C. J.; Bradley, J. P.

2005-01-01

The science return of NASA's Stardust Mission with its valuable cargo of cometary debris hinges on the ability to efficiently extract particles from silica aerogel collectors. The current method for extracting cosmic dust impact tracks is a mature procedure involving sequential perforation of the aerogel with glass needles on computer controlled micromanipulators. This method is highly successful at removing well-defined aerogel fragments of reasonable optical clarity while causing minimal damage to the surrounding aerogel collector tile. Such a system will be adopted by the JSC Astromaterials Curation Facility in anticipation of Stardust s arrival in early 2006. In addition to Stardust, aerogel is a possible collector for future sample return missions and is used for capture of hypervelocity ejecta in high power laser experiments of interest to LLNL. Researchers will be eager to obtain Stardust samples for study as quickly as possible, and rapid extraction tools requiring little construction, training, or investment would be an attractive asset. To this end, we have experimented with micro-blades for the Stardust impact track extraction process. Our ultimate goal is a rapid extraction system in a clean electron beam environment, such as an SEM or dual-beam FIB, for in situ sample preparation, mounting and analysis.

Near-IR Image-Guided Laser Ablation of Demineralization on Tooth Occlusal Surfaces

PubMed Central

Tom, Henry; Chan, Kenneth H.; Darling, Cynthia L.; Fried, Daniel

2016-01-01

Introduction Studies have shown that reflectance images at near-IR wavelengths coincident with higher water absorption are well-suited for image-guided laser ablation of carious lesions since the contrast between sound and demineralized enamel is extremely high and interference from stains is minimized. The objective of this study was to demonstrate that near-IR reflectance images taken at a wavelength range of 1,500–1,700 nm can be used to guide a 9.3 μm CO2 laser for the selective ablation of early demineralization on tooth occlusal surfaces. Methods The occlusal surfaces of ten sound human molars were used in this in vitro study. Shallow simulated caries lesions with random patterns and varying depth and position were produced on tooth occlusal surfaces. Sequential near-IR reflectance images at 1,500–1,700 nm were used to guide the laser for the selective removal of the demineralized enamel. Digital microscopy and polarization sensitive optical coherence tomography (PS-OCT) were used to assess selectivity. Results Images taken before and after lesion removal suggest that the demineralized areas were removed with high selectivity. Although the estimated volume of tissue ablated was typically higher than the initial lesion volume measured with PS-OCT, the volume of enamel removed by the laser correlated well with the initial lesion volume. Conclusion Sequential near-IR reflectance images at 1,500–1,700 nm can be used to guide a 9.3 μm CO2 laser for the selective ablation of early demineralization on tooth occlusal surfaces. PMID:26763111

Comparing the behavioural impact of a nudge-based handwashing intervention to high-intensity hygiene education: a cluster-randomised trial in rural Bangladesh.

PubMed

Grover, Elise; Hossain, Mohammed Kamal; Uddin, Saker; Venkatesh, Mohini; Ram, Pavani K; Dreibelbis, Robert

2018-01-01

To determine the impact of environmental nudges on handwashing behaviours among primary school children as compared to a high-intensity hygiene education intervention. In a cluster-randomised trial (CRT), we compared the rates of handwashing with soap (HWWS) after a toileting event among primary school students in rural Bangladesh. Eligible schools (government run, on-site sanitation and water, no hygiene interventions in last year, fewer than 450 students) were identified, and 20 schools were randomly selected and allocated without blinding to one of four interventions, five schools per group: simultaneous handwashing infrastructure and nudge construction, sequential infrastructure then nudge construction, simultaneous infrastructure and high-intensity hygiene education (HE) and sequential handwashing infrastructure and HE. The primary outcome, incidence of HWWS after a toileting event, was compared between the intervention groups at different data collection points with robust-Poisson regression analysis with generalised estimating equations, adjusting for school-level clustering of outcomes. The nudge intervention and the HE intervention were found to be equally effective at sustained impact over 5 months post-intervention (adjusted IRR 0.81, 95% CI 0.61-1.09). When comparing intervention delivery timing, the simultaneous delivery of the HE intervention significantly outperformed the sequential HE delivery (adjusted IRR 1.58 CI 1.20-2.08), whereas no significant difference was observed between sequential and simultaneous nudge intervention delivery (adjusted IRR 0.75, 95% CI 0.48-1.17). Our trial demonstrates sustained improved handwashing behaviour 5 months after the nudge intervention. The nudge intervention's comparable performance to a high-intensity hygiene education intervention is encouraging. © 2017 John Wiley & Sons Ltd.

EDITORIAL: The 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2007)

NASA Astrophysics Data System (ADS)

Hebling, C.; Woias, P.

2008-10-01

This special issue of Journal of Micromechanics and Microengineering (JMM) contains a selection of papers from the 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion (PowerMEMS 2007). The workshop was held in Freiburg, Germany on 27-29 November 2007 under the joint organization of the Fraunhofer Institute for Solar Energy Systems (FhG-ISE), Freiburg and the Department of Microsystems Engineering (IMTEK) of the Albert-Ludwig-University of Freiburg. PowerMEMS 2007 continues a series of workshops initiated in 2000 in Japan to create an annual discussion forum in the emerging field of micro energy technology. With a single exception in 2001, the workshop has continued as an annual meeting ever since, with a continuous increase in the number of presentations and participants. The program of PowerMEMS 2007 was composed of 2 invited talks, 25 oral talks and 61 poster presentations. From these 88 presentations 16 have been selected for this special issue. It was at the end of 1959 when the Caltech physicist Richard Feynman gave his famous lecture entitled 'There Is Plenty of Room at the Bottom' in which he discussed the possibilities of miniaturization for both storage capacity ('Encyclopaedia Britannica on the head of a pin') as well as micro machining ('rearranging the atoms'), although there were absolutely no technological possibilities in sight for an adequate realization of such ideas. Now, nearly 50 years later, we not only have incredible knowledge about the nanoworld, but even more we are now able to generate microelectromechanical devices which, next to their electronic properties, can integrate physical and analytical functions. Today, Feynman might easily have added a second lecture entitled 'There is Plenty of Energy at the Bottom'. Micro energy technology has seen a tremendous rise in MEMS and material sciences and is regarded today as one of their hot topics. Also, there are more and more companies in this field trying to commercialize micro energy harvesting devices, micro thermo-photovoltaics or micro fuel cells in order to make an impact on our daily life. It is interesting to see the remarkable scientific dynamics and innovations in micro energy technology that have been mirrored in the scope of consecutive PowerMEMS workshops. Micro fuel cells, micro combustion systems and heat engines have been on-going topics from the beginning due to their promising power densities and high power levels up to hundreds of watts. At the other end of the power scale micro energy harvesting has entered the stage, with a remarkable growth rate of presentations during the last three workshops, towering over all other topics with 33 presentations at PowerMEMS 2007. Another significant trend is the slow but steady emergence of electronic energy management as a future key technology. As Guest Editors of this special issue we would like to express our appreciation to the members of the Organizing Committee and the Technical Program Committee of PowerMEMS for their on-going efforts. By selecting the research fields mentioned above they formed the PowerMEMS 2007 program as a comprehensive digest of today's micro energy technology that is reflected, along with selected high quality publications, in this special issue of JMM. We hope that this work will stimulate further innovative research in micro energy technology and will help to mark the trail for further progress in this exciting field of MEMS science and technology.

Protocol for in vitro somatic embryogenesis and regeneration of rice (Oryza sativa L.).

PubMed

Verma, Dipti; Joshi, Rohit; Shukla, Alok; Kumar, Pramod

2011-12-01

Development of highly efficient and reproducible plant regeneration system has tremendous potential to provide improved technology to assist in genetic transformation of indica rice cultivars for their further exploitation in selection. For the development of a highly reproducible regeneration system through somatic embryogenesis, mature embryos of highly popular rice cultivars i.e., Govind (for rainfed areas), Pusa Basmati-1 (aromatic basmati) and Jaya (for irrigated areas) were used. Optimum callus formation (%) to MS medium supplemented with 2, 4-D was obtained at 12.0 microM in Govind, 14.0 microM in Jaya and 15.0 microM in Pusa Basmati-1. All the cultivars showed good proliferation on MS medium without hormone. In Govind, highest embryogenic response was observed in MS medium supplemented with 2, 4-D (0.4 microM) + kinetin (0.4 microM), while in Pusa Basmati-1 with 2, 4-D (0.4 microM) + kinetin (2.0 microM) and in Jaya on hormone-free MS medium. Excellent embryo regeneration in Govind was observed on MS medium supplemented with low concentrations (1.1 microM) of BAP or hormone-free MS medium, while in Pusa Basmati-1 and Jaya embryogenesis was observed on MS medium supplemented with higher concentration of BAP (2.2 microM). Similarly, maximum plantlets with proliferated roots were observed in Govind on hormone-free MS medium, while in Pusa Basmati-1 and Jaya on MS medium supplemented with high concentration of NAA (4.0 microM). Developed plantlets were further successfully acclimatized and grown under pot culture up to maturity. Further the yield potential of in vitro developed plants was accessed at par to the direct seeded one under pot culture. Present, protocol standardizes somatic embryogenesis and efficient regeneration of agronomically important, high yielding and diverse indica rice cultivars which can be utilized as an efficient tool for molecular studies and genetic transformation in future.

Micro-Arcsec mission: implications of the monitoring, diagnostic and calibration of the instrument response in the data reduction chain. .

NASA Astrophysics Data System (ADS)

Busonero, D.; Gai, M.

The goals of 21st century high angular precision experiments rely on the limiting performance associated to the selected instrumental configuration and observational strategy. Both global and narrow angle micro-arcsec space astrometry require that the instrument contributions to the overall error budget has to be less than the desired micro-arcsec level precision. Appropriate modelling of the astrometric response is required for optimal definition of the data reduction and calibration algorithms, in order to ensure high sensitivity to the astrophysical source parameters and in general high accuracy. We will refer to the framework of the SIM-Lite and the Gaia mission, the most challenging space missions of the next decade in the narrow angle and global astrometry field, respectively. We will focus our dissertation on the Gaia data reduction issues and instrument calibration implications. We describe selected topics in the framework of the Astrometric Instrument Modelling for the Gaia mission, evidencing their role in the data reduction chain and we give a brief overview of the Astrometric Instrument Model Data Analysis Software System, a Java-based pipeline under development by our team.

[Pay attention to the application of the international intraocular retinoblastoma classification and sequential multiple modality treatment].

PubMed

Fan, X Q

2017-08-11

Retinoblastoma (RB) is the most common intraocular malignancy in childhood. It may seriously affect vision, and even threaten the life. The early diagnosis rate of RB in China remains low, and the majority of patients are at late phase with high rates of enucleation and mortality. The International Intraocular Retinoblastoma Classification and TNM staging system are guidances for therapeutic choices and bases for prognosis evaluation. Based on the sequential multi-method treatment modality, chemotherapy combined with local therapy is the mainstream in dealing with RB, which may maximize the results of eye saving and even vision retaining. New therapeutic techniques including supra-selective ophthalmic artery interventional chemotherapy and intravitreal chemotherapy can further improve the efficacy of treatment, especially the eye salvage rate. The overall level of RB treatment should be improved by promoting the international staging, new therapeutic techniques, and the sequential multiple modality treatment. (Chin J Ophthalmol, 2017, 53: 561 - 565) .

Pharmacology of a selective cyclooxygenase-2 inhibitor, HN-56249: a novel compound exhibiting a marked preference for the human enzyme in intact cells.

PubMed

Berg, J; Fellier, H; Christoph, T; Kremminger, P; Hartmann, M; Blaschke, H; Rovensky, F; Towart, R; Stimmeder, D

2000-04-01

HN-56249 (3-(2,4-dichlorothiophenoxy)-4-methylsulfonylamino-benzenesu lfonamide), a highly selective cyclooxygenase (COX)-2 inhibitor, is the prototype of a novel series of COX inhibitors comprising bicyclic arylethersulfonamides; of this series HN-56249 is the most potent and selective human COX-2 inhibitor. HN-56249 inhibited platelet aggregation as a measure of COX-1 activity only moderately (IC50 26.5+/-1.7 microM). In LPS-stimulated monocytic cells the release of prostaglandin (PG) F1alpha as a measure of COX-2 was markedly inhibited (IC50 0.027+/-0.001 microM). Thus, HN-56249 showed an approximately 1000-fold selectivity for COX-2 in intact cells. In whole blood assays HN-56249 showed a potent inhibitory activity for COX-2 (IC50 0.78+/-0.37 microM) only. COX-1 was only weakly inhibited (IC50 867+/-181 microM). Hence, HN-56249 exhibited a greater than 1000-fold selectivity for whole blood COX-2. HN-56249 surpassed the COX-2 selectivities of the COX-2 selective inhibitors 3-cyclohexyloxy-4-methylsulfonylamino-nitrobenzene (NS-398) and 6-(2,4-difluorophenoxy)-5-methyl-sulfonylamino-1-indanone (flosulide) in the intact cell assays by eight- and threefold, respectively, and in the whole blood assays by approximately 40-fold. Following i.v. administration HN-56249 inhibited carrageenan-induced rat paw oedema only moderately (ID50 26.2+/-5.7 mg/kg, mean +/- SEM), approximately tenfold less potent than indomethacin (ID50 2.1+/-0.2 mg/kg, mean +/- SEM). After oral administration HN-56249 reversed thermal hyperalgesia in the carrageenan-induced rat paw oedema test, however, some 30-fold less potently than diclofenac. Comparing the inhibitory potency of HN-56249 against human COX-2 with that against murine COX-2 in intact cells revealed a 300-fold selectivity for the human enzyme. Similar effects were observed with other COX-2-selective arylethersulfonamides. In contrast, non-COX-2-selective arylethersulfonamides, including a highly selective COX-1 inhibitor, inhibited human and murine COX-2 approximately equipotently. In conclusion, HN-56249 is a novel potent and highly selective COX-2 inhibitor with a marked preference for the human COX-2 enzyme in vitro. Despite excellent bioavailability and the long plasma half-life of HN-56249, anti-inflammatory effects in rodents were only moderate. We suggest these differing in vitro-in vivo effects observed could be due to significant inflammatory prostaglandin synthesis by COX-1, or to the genetic differences between human and rodent COX-2, or to both.

A New Direction of Cancer Classification: Positive Effect of Low-Ranking MicroRNAs.

PubMed

Li, Feifei; Piao, Minghao; Piao, Yongjun; Li, Meijing; Ryu, Keun Ho

2014-10-01

Many studies based on microRNA (miRNA) expression profiles showed a new aspect of cancer classification. Because one characteristic of miRNA expression data is the high dimensionality, feature selection methods have been used to facilitate dimensionality reduction. The feature selection methods have one shortcoming thus far: they just consider the problem of where feature to class is 1:1 or n:1. However, because one miRNA may influence more than one type of cancer, human miRNA is considered to be ranked low in traditional feature selection methods and are removed most of the time. In view of the limitation of the miRNA number, low-ranking miRNAs are also important to cancer classification. We considered both high- and low-ranking features to cover all problems (1:1, n:1, 1:n, and m:n) in cancer classification. First, we used the correlation-based feature selection method to select the high-ranking miRNAs, and chose the support vector machine, Bayes network, decision tree, k-nearest-neighbor, and logistic classifier to construct cancer classification. Then, we chose Chi-square test, information gain, gain ratio, and Pearson's correlation feature selection methods to build the m:n feature subset, and used the selected miRNAs to determine cancer classification. The low-ranking miRNA expression profiles achieved higher classification accuracy compared with just using high-ranking miRNAs in traditional feature selection methods. Our results demonstrate that the m:n feature subset made a positive impression of low-ranking miRNAs in cancer classification.

FAST TRACK COMMUNICATION: Selective inactivation of micro-organisms with near-infrared femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Tsen, K. T.; Tsen, Shaw-Wei D.; Sankey, Otto F.; Kiang, Juliann G.

2007-11-01

We demonstrate an unconventional and revolutionary method for selective inactivation of micro-organisms by using near-infrared femtosecond laser pulses. We show that if the wavelength and pulse width of the excitation femtosecond laser are appropriately selected, there exists a window in power density that enables us to achieve selective inactivation of target viruses and bacteria without causing cytotoxicity in mammalian cells. This strategy targets the mechanical (vibrational) properties of micro-organisms, and thus its antimicrobial efficacy is likely unaffected by genetic mutation in the micro-organisms. Such a method may be effective against a wide variety of drug resistant micro-organisms and has broad implications in disinfection as well as in the development of novel treatments for viral and bacterial pathogens.

[Early mother-infant interaction and factors negatively affecting parenting].

PubMed

Cerezo, María Angeles; Trenado, Rosa María; Pons-Salvador, Gemma

2006-08-01

The social information-processing model contributes to identifying the psychological processes underlying the construct "sensitivity" in early mother-child interaction. Negative emotional states associated with inadequate self-regulation in coping with stressors affect the mother's attention skills and the processing of the baby's signals. This leads to less synchronous parental practices, particularly unsatisfactory when the baby is unhappy, or crying because the required self-regulation is not provided. This micro-social research studies the sequential profile of maternal reactions to the baby's positive/neutral vs. difficult behaviours and compares them in two groups of dyads, one with mothers who reported high levels of distress and other negative factors for parenting and another group with low levels. The unfavourable circumstances of the high stress group and their negative effects on interaction were observed in some indiscriminate maternal responses and particularly as they reacted to their baby's difficult behaviour, when the mother's regulatory role is more necessary.

GPU accelerated optical coherence tomography angiography using strip-based registration (Conference Presentation)

NASA Astrophysics Data System (ADS)

Heisler, Morgan; Lee, Sieun; Mammo, Zaid; Jian, Yifan; Ju, Myeong Jin; Miao, Dongkai; Raposo, Eric; Wahl, Daniel J.; Merkur, Andrew; Navajas, Eduardo; Balaratnasingam, Chandrakumar; Beg, Mirza Faisal; Sarunic, Marinko V.

2017-02-01

High quality visualization of the retinal microvasculature can improve our understanding of the onset and development of retinal vascular diseases, which are a major cause of visual morbidity and are increasing in prevalence. Optical Coherence Tomography Angiography (OCT-A) images are acquired over multiple seconds and are particularly susceptible to motion artifacts, which are more prevalent when imaging patients with pathology whose ability to fixate is limited. The acquisition of multiple OCT-A images sequentially can be performed for the purpose of removing motion artifact and increasing the contrast of the vascular network through averaging. Due to the motion artifacts, a robust registration pipeline is needed before feature preserving image averaging can be performed. In this report, we present a novel method for a GPU-accelerated pipeline for acquisition, processing, segmentation, and registration of multiple, sequentially acquired OCT-A images to correct for the motion artifacts in individual images for the purpose of averaging. High performance computing, blending CPU and GPU, was introduced to accelerate processing in order to provide high quality visualization of the retinal microvasculature and to enable a more accurate quantitative analysis in a clinically useful time frame. Specifically, image discontinuities caused by rapid micro-saccadic movements and image warping due to smoother reflex movements were corrected by strip-wise affine registration estimated using Scale Invariant Feature Transform (SIFT) keypoints and subsequent local similarity-based non-rigid registration. These techniques improve the image quality, increasing the value for clinical diagnosis and increasing the range of patients for whom high quality OCT-A images can be acquired.

Wavelet Packet Feature Assessment for High-Density Myoelectric Pattern Recognition and Channel Selection toward Stroke Rehabilitation.

PubMed

Wang, Dongqing; Zhang, Xu; Gao, Xiaoping; Chen, Xiang; Zhou, Ping

2016-01-01

This study presents wavelet packet feature assessment of neural control information in paretic upper limb muscles of stroke survivors for myoelectric pattern recognition, taking advantage of high-resolution time-frequency representations of surface electromyogram (EMG) signals. On this basis, a novel channel selection method was developed by combining the Fisher's class separability index and the sequential feedforward selection analyses, in order to determine a small number of appropriate EMG channels from original high-density EMG electrode array. The advantages of the wavelet packet features and the channel selection analyses were further illustrated by comparing with previous conventional approaches, in terms of classification performance when identifying 20 functional arm/hand movements implemented by 12 stroke survivors. This study offers a practical approach including paretic EMG feature extraction and channel selection that enables active myoelectric control of multiple degrees of freedom with paretic muscles. All these efforts will facilitate upper limb dexterity restoration and improved stroke rehabilitation.

A reversible fluorescence "off-on-off" sensor for sequential detection of aluminum and acetate/fluoride ions.

PubMed

Gupta, Vinod Kumar; Mergu, Naveen; Kumawat, Lokesh Kumar; Singh, Ashok Kumar

2015-11-01

A new rhodamine functionalized fluorogenic Schiff base CS was synthesized and its colorimetric and fluorescence responses toward various metal ions were explored. The sensor exhibited highly selective and sensitive colorimetric and "off-on" fluorescence response towards Al(3+) in the presence of other competing metal ions. These spectral changes are large enough in the visible region of the spectrum and thus enable naked-eye detection. Studies proved that the formation of CS-Al(3+) complex is fully reversible and can sense to AcO(-)/F(-) via dissociation. The results revealed that the sensor provides fluorescence "off-on-off" strategy for the sequential detection of Al(3+) and AcO(-)/F(-). Copyright © 2015 Elsevier B.V. All rights reserved.

Bioflavoring by non-conventional yeasts in sequential beer fermentations.

PubMed

Holt, Sylvester; Mukherjee, Vaskar; Lievens, Bart; Verstrepen, Kevin J; Thevelein, Johan M

2018-06-01

Non-conventional yeast species have great capacity for producing diverse flavor profiles in production of alcoholic beverages, but their potential for beer brewing, in particular in consecutive fermentations with Saccharomyces cerevisiae, has only poorly been explored. We have screened 17 non-conventional yeast species for production of an appealing profile of flavor esters and phenolics in the first phase of alcoholic fermentation, followed by inoculation with S. cerevisiae to complete the fermentation. For measurement of phenolic compounds and their precursors we developed an improved and highly sensitive methodology. The results show that non-conventional yeast species possess promising potential for enhancement of desirable flavors in beer production. Notable examples are increasing isoamyl acetate (fruity, banana flavor) by application of P. kluyverii, augmenting ethyl phenolic compounds (spicy notes) with Brettanomyces species and enhancing 4-vinyl guaiacol (clove-like aroma) with T. delbrueckii. All Pichia strains also produced high levels of ethyl acetate (solvent-like flavor). This might be selectively counteracted by selection of an appropriate S. cerevisiae strain for the second fermentation phase, which lowers total ester profile. Hence, optimization of the process conditions and/or proper strain selection in sequentially inoculated fermentations are required to unlock the full potential for aroma improvement by the non-conventional yeast species. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Fabrication of unique 3D microparticles in non-rectangular microchannels with flow lithography

NASA Astrophysics Data System (ADS)

Nam, Sung Min; Kim, Kibeom; Park, Wook; Lee, Wonhee

Invention of flow lithography has offered a simple yet effective method of fabricating micro-particles. However particles produced with conventional techniques were largely limited to 2-dimensional shapes projected to form a column. We proposed inexpensive and simple soft-lithography techniques to fabricate micro-channels with various cross-sectional shapes. The non-rectangular channels are then used to fabricate micro-particles using flow lithography resulting in interesting 3D shapes such as tetrahedrals or half-pyramids. In addition, a microfluidic device capable of fabricating multi-layered micro-particles was developed. On-chip PDMS valves are used to trap and position the particle at the precise location in microchannel with varying cross-section. Multilayer particles are generated by sequential monomer exchange and polymerization along the channel. While conventional multi-layered particles made with droplet generators require their layer materials be dissolved in immiscible fluids, the new method allows diverse choice of materials, not limited to their diffusibility. The multilayer 3D particles can be applied in areas such as drug delivery and tissue engineering.

Electromechanical performance analysis of inflated dielectric elastomer membrane for micro pump applications

NASA Astrophysics Data System (ADS)

Saini, Abhishek; Ahmad, Dilshad; Patra, Karali

2016-04-01

Dielectric elastomers have received a great deal of attention recently as potential materials for many new types of sensors, actuators and future energy generators. When subjected to high electric field, dielectric elastomer membrane sandwiched between compliant electrodes undergoes large deformation with a fast response speed. Moreover, dielectric elastomers have high specific energy density, toughness, flexibility and shape processability. Therefore, dielectric elastomer membranes have gained importance to be applied as micro pumps for microfluidics and biomedical applications. This work intends to extend the electromechanical performance analysis of inflated dielectric elastomer membranes to be applied as micro pumps. Mechanical burst test and cyclic tests were performed to investigate the mechanical breakdown and hysteresis loss of the dielectric membrane, respectively. Varying high electric field was applied on the inflated membrane under different static pressure to determine the electromechanical behavior and nonplanar actuation of the membrane. These tests were repeated for membranes with different pre-stretch values. Results show that pre-stretching improves the electromechanical performance of the inflated membrane. The present work will help to select suitable parameters for designing micro pumps using dielectric elastomer membrane. However this material lacks durability in operation.This issue also needs to be investigated further for realizing practical micro pumps.

Functional micro/nanostructures: simple synthesis and application in sensors, fuel cells, and gene delivery.

PubMed

Guo, Shaojun; Wang, Erkang

2011-07-19

In order to develop new, high technology devices for a variety of applications, researchers would like to better control the structure and function of micro/nanomaterials through an understanding of the role of size, shape, architecture, composition, hybridization, molecular engineering, assembly, and microstructure. However, researchers continue to face great challenges in the construction of well-defined micro/nanomaterials with diverse morphologies. At the same time, the research interface where micro/nanomaterials meet electrochemistry, analytical chemistry, biomedicine, and other fields provides rich opportunities to reveal new chemical, physical, and biological properties of micro/nanomaterials and to uncover many new functions and applications of these materials. In this Account, we describe our recent progress in the construction of novel inorganic and polymer nanostructures formed through different simple strategies. Our synthetic strategies include wet-chemical and electrochemical methods for the controlled production of inorganic and polymer nanomaterials with well-defined morphologies. These methods are both facile and reliable, allowing us to produce high-quality micro/nanostructures, such as nanoplates, micro/nanoflowers, monodisperse micro/nanoparticles, nanowires, nanobelts, and polyhedron and even diverse hybrid structures. We implemented a series of approaches to address the challenges in the preparation of new functional micro/nanomaterials for a variety of important applications This Account also highlights new or enhanced applications of certain micro/nanomaterials in sensing applications. We singled out analytical techniques that take advantage of particular properties of micro/nanomaterials. Then by rationally tailoring experimental parameters, we readily and selectively obtained different types of micro/nanomaterials with novel morphologies with high performance in applications such as electrochemical sensors, electrochemiluminescent sensors, gene delivery agents, and fuel cell catalysts. We expect that micro/nanomaterials with unique structural characteristics, properties, and functions will attract increasing research interest and will lead to new opportunities in various fields of research.

Selective deposition of nanostructured ruthenium oxide using Tobacco mosaic virus for micro-supercapacitors in solid Nafion electrolyte

NASA Astrophysics Data System (ADS)

Gnerlich, Markus; Ben-Yoav, Hadar; Culver, James N.; Ketchum, Douglas R.; Ghodssi, Reza

2015-10-01

A three-dimensional micro-supercapacitor has been developed using a novel bottom-up assembly method combining genetically modified Tobacco mosaic virus (TMV-1Cys), photolithographically defined micropillars and selective deposition of ruthenium oxide on multi-metallic microelectrodes. The three-dimensional microelectrodes consist of a titanium nitride current collector with two functionalized areas: (1) gold coating on the active electrode area promotes TMV-1Cys adhesion, and (2) sacrificial nickel pads dissolve in ruthenium tetroxide plating solution to produce ruthenium oxide on all electrically connected areas. The microfabricated electrodes are arranged in an interdigitated pattern, and the capacitance per electrode has been measured as high as 203 mF cm-2 with solid Nafion electrolyte. The process integration of bio-templated ruthenium oxide with microfabricated electrodes and solid electrolyte is an important advance towards the energy storage needs of mass produced self-sufficient micro-devices.

Selective deposition of nanostructured ruthenium oxide using Tobacco mosaic virus for micro-supercapacitors in solid Nafion electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gnerlich, Markus; Ben-Yoav, Hadar; Culver, James N.

A three-dimensional micro-supercapacitor has been developed using a novel bottom-up assembly method combining genetically modified Tobacco mosaic virus (TMV-1Cys), photolithographically defined micropillars and selective deposition of ruthenium oxide on multi-metallic microelectrodes. The three-dimensional microelectrodes consist of a titanium nitride current collector with two functionalized areas: (1) gold coating on the active electrode area promotes TMV-1Cys adhesion, and (2) sacrificial nickel pads dissolve in ruthenium tetroxide plating solution to produce ruthenium oxide on all electrically connected areas. The microfabricated electrodes are arranged in an interdigitated pattern, and the capacitance per electrode has been measured as high as 203 mF cm-2 withmore » solid Nafion electrolyte. The process integration of bio-templated ruthenium oxide with microfabricated electrodes and solid electrolyte is an important advance towards the energy storage needs of mass produced self-sufficient micro-devices.« less

Learning Behavior Characterization with Multi-Feature, Hierarchical Activity Sequences

ERIC Educational Resources Information Center

Ye, Cheng; Segedy, James R.; Kinnebrew, John S.; Biswas, Gautam

2015-01-01

This paper discusses Multi-Feature Hierarchical Sequential Pattern Mining, MFH-SPAM, a novel algorithm that efficiently extracts patterns from students' learning activity sequences. This algorithm extends an existing sequential pattern mining algorithm by dynamically selecting the level of specificity for hierarchically-defined features…

A Two-Locus Model of the Evolution of Insecticide Resistance to Inform and Optimise Public Health Insecticide Deployment Strategies

PubMed Central

2017-01-01

We develop a flexible, two-locus model for the spread of insecticide resistance applicable to mosquito species that transmit human diseases such as malaria. The model allows differential exposure of males and females, allows them to encounter high or low concentrations of insecticide, and allows selection pressures and dominance values to differ depending on the concentration of insecticide encountered. We demonstrate its application by investigating the relative merits of sequential use of insecticides versus their deployment as a mixture to minimise the spread of resistance. We recover previously published results as subsets of this model and conduct a sensitivity analysis over an extensive parameter space to identify what circumstances favour mixtures over sequences. Both strategies lasted more than 500 mosquito generations (or about 40 years) in 24% of runs, while in those runs where resistance had spread to high levels by 500 generations, 56% favoured sequential use and 44% favoured mixtures. Mixtures are favoured when insecticide effectiveness (their ability to kill homozygous susceptible mosquitoes) is high and exposure (the proportion of mosquitoes that encounter the insecticide) is low. If insecticides do not reliably kill homozygous sensitive genotypes, it is likely that sequential deployment will be a more robust strategy. Resistance to an insecticide always spreads slower if that insecticide is used in a mixture although this may be insufficient to outperform sequential use: for example, a mixture may last 5 years while the two insecticides deployed individually may last 3 and 4 years giving an overall ‘lifespan’ of 7 years for sequential use. We emphasise that this paper is primarily about designing and implementing a flexible modelling strategy to investigate the spread of insecticide resistance in vector populations and demonstrate how our model can identify vector control strategies most likely to minimise the spread of insecticide resistance. PMID:28095406

Computationally inexpensive identification of noninformative model parameters by sequential screening

NASA Astrophysics Data System (ADS)

Cuntz, Matthias; Mai, Juliane; Zink, Matthias; Thober, Stephan; Kumar, Rohini; Schäfer, David; Schrön, Martin; Craven, John; Rakovec, Oldrich; Spieler, Diana; Prykhodko, Vladyslav; Dalmasso, Giovanni; Musuuza, Jude; Langenberg, Ben; Attinger, Sabine; Samaniego, Luis

2015-08-01

Environmental models tend to require increasing computational time and resources as physical process descriptions are improved or new descriptions are incorporated. Many-query applications such as sensitivity analysis or model calibration usually require a large number of model evaluations leading to high computational demand. This often limits the feasibility of rigorous analyses. Here we present a fully automated sequential screening method that selects only informative parameters for a given model output. The method requires a number of model evaluations that is approximately 10 times the number of model parameters. It was tested using the mesoscale hydrologic model mHM in three hydrologically unique European river catchments. It identified around 20 informative parameters out of 52, with different informative parameters in each catchment. The screening method was evaluated with subsequent analyses using all 52 as well as only the informative parameters. Subsequent Sobol's global sensitivity analysis led to almost identical results yet required 40% fewer model evaluations after screening. mHM was calibrated with all and with only informative parameters in the three catchments. Model performances for daily discharge were equally high in both cases with Nash-Sutcliffe efficiencies above 0.82. Calibration using only the informative parameters needed just one third of the number of model evaluations. The universality of the sequential screening method was demonstrated using several general test functions from the literature. We therefore recommend the use of the computationally inexpensive sequential screening method prior to rigorous analyses on complex environmental models.

Computationally inexpensive identification of noninformative model parameters by sequential screening

NASA Astrophysics Data System (ADS)

Mai, Juliane; Cuntz, Matthias; Zink, Matthias; Thober, Stephan; Kumar, Rohini; Schäfer, David; Schrön, Martin; Craven, John; Rakovec, Oldrich; Spieler, Diana; Prykhodko, Vladyslav; Dalmasso, Giovanni; Musuuza, Jude; Langenberg, Ben; Attinger, Sabine; Samaniego, Luis

2016-04-01

Environmental models tend to require increasing computational time and resources as physical process descriptions are improved or new descriptions are incorporated. Many-query applications such as sensitivity analysis or model calibration usually require a large number of model evaluations leading to high computational demand. This often limits the feasibility of rigorous analyses. Here we present a fully automated sequential screening method that selects only informative parameters for a given model output. The method requires a number of model evaluations that is approximately 10 times the number of model parameters. It was tested using the mesoscale hydrologic model mHM in three hydrologically unique European river catchments. It identified around 20 informative parameters out of 52, with different informative parameters in each catchment. The screening method was evaluated with subsequent analyses using all 52 as well as only the informative parameters. Subsequent Sobol's global sensitivity analysis led to almost identical results yet required 40% fewer model evaluations after screening. mHM was calibrated with all and with only informative parameters in the three catchments. Model performances for daily discharge were equally high in both cases with Nash-Sutcliffe efficiencies above 0.82. Calibration using only the informative parameters needed just one third of the number of model evaluations. The universality of the sequential screening method was demonstrated using several general test functions from the literature. We therefore recommend the use of the computationally inexpensive sequential screening method prior to rigorous analyses on complex environmental models.

Selective area growth of N-polar GaN nanorods by plasma-assisted MBE on micro-cone-patterned c-sapphire substrates

NASA Astrophysics Data System (ADS)

Jmerik, V. N.; Kuznetsova, N. V.; Nechaev, D. V.; Shubina, T. V.; Kirilenko, D. A.; Troshkov, S. I.; Davydov, V. Yu.; Smirnov, A. N.; Ivanov, S. V.

2017-11-01

The site-controlled selective area growth of N-polar GaN nanorods (NR) was developed by plasma-assisted MBE (PA MBE) on micro-cone-patterned sapphire substrates (μ-CPSS) by using a two-stage growth process. A GaN nucleation layer grown by migration enhanced epitaxy provides the best selectivity for nucleation of NRs on the apexes of 3.5-μm-diameter cones, whereas the subsequent growth of 1-μm-high NRs with a constant diameter of about 100 nm proceeds by standard high-temperature PA MBE at nitrogen-rich conditions. These results are explained by anisotropy of the surface energy for GaN of different polarity and crystal orientation. The InGaN single quantum wells inserted in the GaN NRs grown on the μ-CPSS demonstrate photoluminescence at 510 nm with a spatially periodic variation of its intensity with a period of ∼6 μm equal to that of the substrate patterning profile.

High-throughput platform assay technology for the discovery of pre-microrna-selective small molecule probes.

PubMed

Lorenz, Daniel A; Song, James M; Garner, Amanda L

2015-01-21

MicroRNAs (miRNA) play critical roles in human development and disease. As such, the targeting of miRNAs is considered attractive as a novel therapeutic strategy. A major bottleneck toward this goal, however, has been the identification of small molecule probes that are specific for select RNAs and methods that will facilitate such discovery efforts. Using pre-microRNAs as proof-of-concept, herein we report a conceptually new and innovative approach for assaying RNA-small molecule interactions. Through this platform assay technology, which we term catalytic enzyme-linked click chemistry assay or cat-ELCCA, we have designed a method that can be implemented in high throughput, is virtually free of false readouts, and is general for all nucleic acids. Through cat-ELCCA, we envision the discovery of selective small molecule ligands for disease-relevant miRNAs to promote the field of RNA-targeted drug discovery and further our understanding of the role of miRNAs in cellular biology.

A fast and accurate online sequential learning algorithm for feedforward networks.

PubMed

Liang, Nan-Ying; Huang, Guang-Bin; Saratchandran, P; Sundararajan, N

2006-11-01

In this paper, we develop an online sequential learning algorithm for single hidden layer feedforward networks (SLFNs) with additive or radial basis function (RBF) hidden nodes in a unified framework. The algorithm is referred to as online sequential extreme learning machine (OS-ELM) and can learn data one-by-one or chunk-by-chunk (a block of data) with fixed or varying chunk size. The activation functions for additive nodes in OS-ELM can be any bounded nonconstant piecewise continuous functions and the activation functions for RBF nodes can be any integrable piecewise continuous functions. In OS-ELM, the parameters of hidden nodes (the input weights and biases of additive nodes or the centers and impact factors of RBF nodes) are randomly selected and the output weights are analytically determined based on the sequentially arriving data. The algorithm uses the ideas of ELM of Huang et al. developed for batch learning which has been shown to be extremely fast with generalization performance better than other batch training methods. Apart from selecting the number of hidden nodes, no other control parameters have to be manually chosen. Detailed performance comparison of OS-ELM is done with other popular sequential learning algorithms on benchmark problems drawn from the regression, classification and time series prediction areas. The results show that the OS-ELM is faster than the other sequential algorithms and produces better generalization performance.

MicroRNA Expression Profile Selection for Cancer Staging Classification Using Backpropagation

NASA Astrophysics Data System (ADS)

Anjarwati; Wibowo, Adi; Adhy, Satriyo; Kusumaningrum, Retno

2018-05-01

Ovarian cancer, breast cancer, and lung cancer are deadly diseases and require serious treatment. The cancers are among the fifth most common causes of cancer-induced deaths especially for woman. The high mortality rate of cancer is caused by the lack of effective strategies for early detection of the cancer, whereas if its detected in the early stages, the life survival of cancer patients will be 90%, otherwise the survival rate only 30% when the cancers detected on metastasis stages or cancer cells have spread from a primary site of cancer. MicroRNAs can be used as potential biomarkers for cancer due to their profile expression on the cancers. In this paper, we proposed the feature selection of microRNA expression profiles for classification of the cancers stages using Backpropagation Neural Network. The Cancer stages are classified into before metastasis and after metastasis. Several combinations of the microRNA expression profiles from medical references are compared to find the best features for the classification. The accuracy and the mean square errors are used as basis testing the comparison.

Ontology-oriented retrieval of putative microRNAs in Vitis vinifera via GrapeMiRNA: a web database of de novo predicted grape microRNAs.

PubMed

Lazzari, Barbara; Caprera, Andrea; Cestaro, Alessandro; Merelli, Ivan; Del Corvo, Marcello; Fontana, Paolo; Milanesi, Luciano; Velasco, Riccardo; Stella, Alessandra

2009-06-29

Two complete genome sequences are available for Vitis vinifera Pinot noir. Based on the sequence and gene predictions produced by the IASMA, we performed an in silico detection of putative microRNA genes and of their targets, and collected the most reliable microRNA predictions in a web database. The application is available at http://www.itb.cnr.it/ptp/grapemirna/. The program FindMiRNA was used to detect putative microRNA genes in the grape genome. A very high number of predictions was retrieved, calling for validation. Nine parameters were calculated and, based on the grape microRNAs dataset available at miRBase, thresholds were defined and applied to FindMiRNA predictions having targets in gene exons. In the resulting subset, predictions were ranked according to precursor positions and sequence similarity, and to target identity. To further validate FindMiRNA predictions, comparisons to the Arabidopsis genome, to the grape Genoscope genome, and to the grape EST collection were performed. Results were stored in a MySQL database and a web interface was prepared to query the database and retrieve predictions of interest. The GrapeMiRNA database encompasses 5,778 microRNA predictions spanning the whole grape genome. Predictions are integrated with information that can be of use in selection procedures. Tools added in the web interface also allow to inspect predictions according to gene ontology classes and metabolic pathways of targets. The GrapeMiRNA database can be of help in selecting candidate microRNA genes to be validated.

MicroRNA Detection by DNA-Mediated Liposome Fusion.

PubMed

Jumeaux, Coline; Wahlsten, Olov; Block, Stephan; Kim, Eunjung; Chandrawati, Rona; Howes, Philip D; Höök, Fredrik; Stevens, Molly M

2018-03-02

Membrane fusion is a process of fundamental importance in biological systems that involves highly selective recognition mechanisms for the trafficking of molecular and ionic cargos. Mimicking natural membrane fusion mechanisms for the purpose of biosensor development holds great potential for amplified detection because relatively few highly discriminating targets lead to fusion and an accompanied engagement of a large payload of signal-generating molecules. In this work, sequence-specific DNA-mediated liposome fusion is used for the highly selective detection of microRNA. The detection of miR-29a, a known flu biomarker, is demonstrated down to 18 nm within 30 min with high specificity by using a standard laboratory microplate reader. Furthermore, one order of magnitude improvement in the limit of detection is demonstrated by using a novel imaging technique combined with an intensity fluctuation analysis, which is coined two-color fluorescence correlation microscopy. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

EDITORIAL: Selected papers from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011) Selected papers from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011)

NASA Astrophysics Data System (ADS)

Cho, Young-Ho

2012-09-01

This special section of Journal of Micromechanics and Microengineering features papers selected from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011), held at Sejong Hotel in Seoul, Korea during 15-18 November 2011. Since the first PowerMEMS workshop held in Sendai, Japan in 2000, the workshop has developed as the premier forum for reporting research results in micro and nanotechnology for power generation, energy conversion, harvesting and processing applications, including in-depth technical issues on nanostructures and materials for small-scale high-density energy and thermal management. Potential PowerMEMS applications cover not only portable power devices for consumer electronics and remote sensors, but also micro engines, impulsive thrusters and fuel cells for systems ranging from the nanometer to the millimeter scale. The 2011 technical program consists of 1 plenary talk, 4 invited talks and 118 contributed presentations. The 48 oral and 70 poster presentations, selected by 27 Technical Program Committee Members from 131 submitted abstracts, have stimulated lively discussion maximizing the interaction between participants. Among them, this special section includes 9 papers covering micro-scale power generators, energy converters, harvesters, thrusters and thermal coolers. Finally, we are grateful to the members of the International Steering Committee, the Technical Program Committee, and the Local Organizing Committee for their efforts and contributions to PowerMEMS 2011. We also thank the two companies Samsung Electro-Mechanics and LG Elite for technical tour arrangements. Special thanks go to Dr Ian Forbes, the editorial staff of the Journal of Micromechanics and Microengineering, as well as to the staff of IOP Publishing for making this special section possible.

Destruction of Bacillus cereus spores in a thick soy bean paste (doenjang) by continuous ohmic heating with five sequential electrodes.

PubMed

Ryang, J H; Kim, N H; Lee, B S; Kim, C T; Rhee, M S

2016-07-01

This study selected spores from Bacillus cereus FSP-2 strain (the isolate from a commercial doenjang processing line) as the test strain which showed significantly higher thermal resistance (P < 0·05) than B. cereus reference strain (ATCC 27348). The spores in doenjang were subjected to ohmic heating (OH) at 95, 105, 115 and 125°C for 30, 60 or 90 s using a five sequential electrode system (electrical field: 26·7 V cm(-1) ; alternating current frequency: 25 kHz). OH at 105°C for 30-90 s reduced the B. cereus spore count in doenjang samples to <4 log CFU g(-1) . Since OH treatment at 115 and 125°C caused a perceivable colour change in the product (>1·5 National Bureau of Standards units), treatment at 105°C for 60 s was selected and applied on a large scale (500 kg of product). Reliable and reproducible destruction of B. cereus spores occurred; the reductions achieved (to < 4 log CFU g(-1) ) met the Korean national standards. Scanning electron microscopy revealed microstructural alterations in the spores (shrinkage and a distorted outer spore coat). OH is an effective method for destroying B. cereus spores to ensure the microbiological quality and safety of a thick, highly viscous sauce. This study shows that an ohmic heating (OH) using a five sequential electrode system can effectively destroy highly heat-resistant Bacillus cereus spores which have been frequently found in a commercial doenjang processing line without perceivable quality change in the product. In addition, it may demonstrate high potential of the unique OH system used in this study that will further contribute to ensure microbiological quality and safety of crude sauces containing high levels of electrolyte other than doenjang as well. © 2016 The Society for Applied Microbiology.

Combining micro-structures and micro-algae to increase lipid production for bio-fuel

NASA Astrophysics Data System (ADS)

Vyawahare, Saurabh; Zhu, Emilly; Mestler, Troy; Estévez-Torres, André.; Austin, Robert

2011-03-01

3rd generation bio-fuels like lipid producing micro-algae are a promising source of energy that could replace our dependence on petroleum. However, until there are improvements in algae oil yields, and a reduction in the energy needed for processing, algae bio-fuels are not economically competitive with petroleum. Here, we describe our work combining micro-fabricated devices with micro-algae Neochloris oleoabundans, a species first isolated on the sand dunes of Saudi Arabia. Inserting micro-algae of varying fitness into a landscape of micro-habitats allows us to evolve and select them based on a variety of conditions like specific gravity, starvation response and Nile Red fluorescence (which is a marker for lipid production). Hence, we can both estimate the production of lipids and generate conditions that allow the creation and isolation of algae which produce higher amounts of lipids, while discarding the rest. Finally, we can use micro-fabricated structures and flocculation to de-water these high lipid producing algae, reducing the need for expensive centrifugation and filtration.

Micro Fluidic Channel Machining on Fused Silica Glass Using Powder Blasting

PubMed Central

Jang, Ho-Su; Cho, Myeong-Woo; Park, Dong-Sam

2008-01-01

In this study, micro fluid channels are machined on fused silica glass via powder blasting, a mechanical etching process, and the machining characteristics of the channels are experimentally evaluated. In the process, material removal is performed by the collision of micro abrasives injected by highly compressed air on to the target surface. This approach can be characterized as an integration of brittle mode machining based on micro crack propagation. Fused silica glass, a high purity synthetic amorphous silicon dioxide, is selected as a workpiece material. It has a very low thermal expansion coefficient and excellent optical qualities and exceptional transmittance over a wide spectral range, especially in the ultraviolet range. The powder blasting process parameters affecting the machined results are injection pressure, abrasive particle size and density, stand-off distance, number of nozzle scanning, and shape/size of the required patterns. In this study, the influence of the number of nozzle scanning, abrasive particle size, and pattern size on the formation of micro channels is investigated. Machined shapes and surface roughness are measured using a 3-dimensional vision profiler and the results are discussed. PMID:27879730

Refractive multiple optical tweezers for parallel biochemical analysis in micro-fluidics

NASA Astrophysics Data System (ADS)

Merenda, Fabrice; Rohner, Johann; Pascoal, Pedro; Fournier, Jean-Marc; Vogel, Horst; Salathé, René-Paul

2007-02-01

We present a multiple laser tweezers system based on refractive optics. The system produces an array of 100 optical traps thanks to a refractive microlens array, whose focal plane is imaged into the focal plane of a high-NA microscope objective. This refractive multi-tweezers system is combined to micro-fluidics, aiming at performing simultaneous biochemical reactions on ensembles of free floating objects. Micro-fluidics allows both transporting the particles to the trapping area, and conveying biochemical reagents to the trapped particles. Parallel trapping in micro-fluidics is achieved with polystyrene beads as well as with native vesicles produced from mammalian cells. The traps can hold objects against fluid flows exceeding 100 micrometers per second. Parallel fluorescence excitation and detection on the ensemble of trapped particles is also demonstrated. Additionally, the system is capable of selectively and individually releasing particles from the tweezers array using a complementary steerable laser beam. Strategies for high-yield particle capture and individual particle release in a micro-fluidic environment are discussed. A comparison with diffractive optical tweezers enhances the pros and cons of refractive systems.

Antimicrobial efficiency of ethanol and 2-propanol alcohols used on contaminated storage phosphor plates and impact on durability of the plate

PubMed Central

Wenzel, A; Kornum, F; Knudsen, MR; Lau, E Frandsen

2013-01-01

Objectives: To assess (1) antimicrobial efficiency of wiping intraoral phosphor plates with alcohol tissues based on ethanol or 2-propanol alcohols after contamination with Candida albicans and Streptococcus oralis, (2) a concept for autodisinfection with ultraviolet light of the transport ramp in a scanner for phosphor plates and (3) the impact of wiping with alcohol tissues on durability of the plate. Methods: Suspensions of C. albicans and S. oralis were prepared in concentrations of 109 and 105 organisms per ml, and Digora (Digora® Optime Imaging Plate, size 2; Soredex, PalaDEx Group Brenntag Nordic A/S, Hellerup, Denmark) and Vista (VistaScan® Imaging Plate PLUS, size 2; Dürr Dental AG, Bietigheim-Bissingen, Germany) plates were contaminated. The plates were wiped with ethanol or 2-propanol disinfectant tissues and imprints obtained on agar. Number of microbial colonies after culturing was recorded. The scanner ramp was contaminated with C. albicans or S. oralis, respectively, the ultraviolet light (UV light) disinfection in the scanner was activated and the number of colonies after culturing was recorded. Plates from each system were sequentially wiped (5–60 times) with ethanol and 2-propanol, exposed and scanned. 48 images from each system were scored blind: 1 = no artefact, 2 = small artefacts and 3 = severe artefacts. Results: Ethanol eliminated C. albicans and S. oralis in high and low concentrations from both types of plates, whereas 2-propanol did not eliminate all micro-organisms at high concentrations. The UV light eliminated all micro-organisms from the ramp. Ethanol degraded the plates to a larger extent than did 2-propanol. Images from Vista plates showed severe artefacts after wiping with ethanol; those from Digora plates did not. Conclusions: Ethanol eliminated all micro-organisms but degraded phosphor plates, whereas 2-propanol did not eliminate all micro-organisms and still degraded plates from Vista but not from Digora. PMID:23420856

Antimicrobial efficiency of ethanol and 2-propanol alcohols used on contaminated storage phosphor plates and impact on durability of the plate.

PubMed

Wenzel, A; Kornum, F; Knudsen, Mr; Lau, E Frandsen

2013-01-01

To assess (1) antimicrobial efficiency of wiping intraoral phosphor plates with alcohol tissues based on ethanol or 2-propanol alcohols after contamination with Candida albicans and Streptococcus oralis, (2) a concept for autodisinfection with ultraviolet light of the transport ramp in a scanner for phosphor plates and (3) the impact of wiping with alcohol tissues on durability of the plate. Suspensions of C. albicans and S. oralis were prepared in concentrations of 10(9) and 10(5) organisms per ml, and Digora (Digora(®) Optime Imaging Plate, size 2; Soredex, PalaDEx Group Brenntag Nordic A/S, Hellerup, Denmark) and Vista (VistaScan(®) Imaging Plate PLUS, size 2; Dürr Dental AG, Bietigheim-Bissingen, Germany) plates were contaminated. The plates were wiped with ethanol or 2-propanol disinfectant tissues and imprints obtained on agar. Number of microbial colonies after culturing was recorded. The scanner ramp was contaminated with C. albicans or S. oralis, respectively, the ultraviolet light (UV light) disinfection in the scanner was activated and the number of colonies after culturing was recorded. Plates from each system were sequentially wiped (5-60 times) with ethanol and 2-propanol, exposed and scanned. 48 images from each system were scored blind: 1 = no artefact, 2 = small artefacts and 3 = severe artefacts. Ethanol eliminated C. albicans and S. oralis in high and low concentrations from both types of plates, whereas 2-propanol did not eliminate all micro-organisms at high concentrations. The UV light eliminated all micro-organisms from the ramp. Ethanol degraded the plates to a larger extent than did 2-propanol. Images from Vista plates showed severe artefacts after wiping with ethanol; those from Digora plates did not. Ethanol eliminated all micro-organisms but degraded phosphor plates, whereas 2-propanol did not eliminate all micro-organisms and still degraded plates from Vista but not from Digora.

Risk factors for arbovirus infections in a low-income community of Rio de Janeiro, Brazil, 2015-2016

PubMed Central

Daumas, Regina Paiva; de Almeida, Andrea Sobral; dos Santos, Reinaldo Souza; Koster, Isabella; Rodrigues, Pedro Pinheiro; Gomes, Marcelly de Freitas; Macedo, Auriane de Fátima; Gerardi, Alyssa; Leite, Iúri da Costa

2018-01-01

Background Dengue epidemics have occurred in the city of Rio de Janeiro (Brazil) since 1986. In the year 2015, Zika and chikungunya viruses were introduced in the city, causing sequential and simultaneous epidemics. Poor socioeconomic conditions have been suggested as contributing factors of arboviral infection. Objective To describe the spatial distribution of human cases of symptomatic arboviral infections and to identify risk factors for infection in a poor community of Rio de Janeiro in the years 2015 and 2016. Methods We built thematic maps of incidence rates for 78 micro-areas in the Manguinhos neighborhood. The micro-areas congregate about 600 inhabitants. Simple and multiple multilevel logistic regression models were used to evaluate the association between the incidence of arboviral diseases and socio-demographic factors at both the individual and micro-area levels. Results From 2015 to 2016, 370 human cases of arbovirus infection were reported in the Manguinhos community: 123 in 2015 and 247 in 2016. There was a significant difference in the risk of arbovirus diseases among different micro-areas, but this was not explained by water and sanitation indicators. The cumulative incidence rate was 849/100,000 in two years. The incidence was greater in those individuals with familiar vulnerability (1,156/100,000 vs. 794/100,000). The multilevel adjusted model showed that the odds of acquiring an arbovirus infection was 55% greater in those with familiar vulnerability. Conclusion Arbovirus infections cause a high burden of disease in Brazilian urban centers. Our results suggest that even in poor neighborhoods, there is a high spatial variability in the risk of acquiring an arbovirus infection. The conditions that favor vector proliferation and infection by arboviruses are complex and involve both individual and environmental characteristics that vary from place to place. To reduce the burden of arboviral diseases, continued public health policies and basic services should be provided to the communities at risk that consider specific local needs. PMID:29879155

Direct biomechanical modeling of trabecular bone using a nonlinear manifold-based volumetric representation

NASA Astrophysics Data System (ADS)

Jin, Dakai; Lu, Jia; Zhang, Xiaoliu; Chen, Cheng; Bai, ErWei; Saha, Punam K.

2017-03-01

Osteoporosis is associated with increased fracture risk. Recent advancement in the area of in vivo imaging allows segmentation of trabecular bone (TB) microstructures, which is a known key determinant of bone strength and fracture risk. An accurate biomechanical modelling of TB micro-architecture provides a comprehensive summary measure of bone strength and fracture risk. In this paper, a new direct TB biomechanical modelling method using nonlinear manifold-based volumetric reconstruction of trabecular network is presented. It is accomplished in two sequential modules. The first module reconstructs a nonlinear manifold-based volumetric representation of TB networks from three-dimensional digital images. Specifically, it starts with the fuzzy digital segmentation of a TB network, and computes its surface and curve skeletons. An individual trabecula is identified as a topological segment in the curve skeleton. Using geometric analysis, smoothing and optimization techniques, the algorithm generates smooth, curved, and continuous representations of individual trabeculae glued at their junctions. Also, the method generates a geometrically consistent TB volume at junctions. In the second module, a direct computational biomechanical stress-strain analysis is applied on the reconstructed TB volume to predict mechanical measures. The accuracy of the method was examined using micro-CT imaging of cadaveric distal tibia specimens (N = 12). A high linear correlation (r = 0.95) between TB volume computed using the new manifold-modelling algorithm and that directly derived from the voxel-based micro-CT images was observed. Young's modulus (YM) was computed using direct mechanical analysis on the TB manifold-model over a cubical volume of interest (VOI), and its correlation with the YM, computed using micro-CT based conventional finite-element analysis over the same VOI, was examined. A moderate linear correlation (r = 0.77) was observed between the two YM measures. This preliminary results show the accuracy of the new nonlinear manifold modelling algorithm for TB, and demonstrate the feasibility of a new direct mechanical strain-strain analysis on a nonlinear manifold model of a highly complex biological structure.

A Feature Selection Algorithm to Compute Gene Centric Methylation from Probe Level Methylation Data.

PubMed

Baur, Brittany; Bozdag, Serdar

2016-01-01

DNA methylation is an important epigenetic event that effects gene expression during development and various diseases such as cancer. Understanding the mechanism of action of DNA methylation is important for downstream analysis. In the Illumina Infinium HumanMethylation 450K array, there are tens of probes associated with each gene. Given methylation intensities of all these probes, it is necessary to compute which of these probes are most representative of the gene centric methylation level. In this study, we developed a feature selection algorithm based on sequential forward selection that utilized different classification methods to compute gene centric DNA methylation using probe level DNA methylation data. We compared our algorithm to other feature selection algorithms such as support vector machines with recursive feature elimination, genetic algorithms and ReliefF. We evaluated all methods based on the predictive power of selected probes on their mRNA expression levels and found that a K-Nearest Neighbors classification using the sequential forward selection algorithm performed better than other algorithms based on all metrics. We also observed that transcriptional activities of certain genes were more sensitive to DNA methylation changes than transcriptional activities of other genes. Our algorithm was able to predict the expression of those genes with high accuracy using only DNA methylation data. Our results also showed that those DNA methylation-sensitive genes were enriched in Gene Ontology terms related to the regulation of various biological processes.

Kullback-Leibler information function and the sequential selection of experiments to discriminate among several linear models. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Sidik, S. M.

1972-01-01

A sequential adaptive experimental design procedure for a related problem is studied. It is assumed that a finite set of potential linear models relating certain controlled variables to an observed variable is postulated, and that exactly one of these models is correct. The problem is to sequentially design most informative experiments so that the correct model equation can be determined with as little experimentation as possible. Discussion includes: structure of the linear models; prerequisite distribution theory; entropy functions and the Kullback-Leibler information function; the sequential decision procedure; and computer simulation results. An example of application is given.

EDITORIAL: The 19th MicroMechanics Europe Workshop (MME 2008) The 19th MicroMechanics Europe Workshop (MME 2008)

NASA Astrophysics Data System (ADS)

Schnakenberg, Uwe

2009-07-01

This special issue of Journal of Micromechanics and Microengineering is devoted to the 19th MicroMechanics Europe Workshop (MME 08), which took place at the RWTH Aachen University, Aachen, Germany, from 28-30 September, 2008. The workshop is a well recognized and established European event in the field of micro system technology using thin-film technologies for creating micro components, micro sensors, micro actuators, and micro systems. The first MME Workshop was held 1989 in Enschede (The Netherlands) and continued 1990 in Berlin (Germany), 1992 in Leuven (Belgium), and then was held annually in Neuchâtel (Switzerland), Pisa (Italy), Copenhagen (Denmark), Barcelona (Spain), Southampton (UK), Ulvik in Hardanger (Norway), Gif-sur-Yvette (France), Uppsala (Sweden), Cork (Ireland), Sinaia (Romania), Delft (The Netherlands), Leuven (Belgium), Göteborg (Sweden), Southampton (UK), and in Guimarães (Portugal). The two day workshop was attended by 180 delegates from 26 countries all over Europe and from Armenia, Austria, Bulgaria, Canada, China, Cuba, Iran, Japan, Korea, Malaysia, Taiwan, Turkey, and the United States of America. A total of 97 papers were accepted for presentation and there were a further five keynote presentations. I am proud to present 22 high-quality papers from MME 2008 selected for their novelty and relevance to Journal of Micromechanics and Microengineering. All the papers went through the regular reviewing procedure of IOP Publishing. I am eternally grateful to all the referees for their excellent work. I would also like to extend my thanks to the members of the Programme Committee of MME 2008, Dr Reinoud Wolffenbuttel, Professor José Higino Correia, and Dr Patrick Pons for pre-selection of the papers as well as to Professor Robert Puers for advice on the final selection of papers. My thanks also go to Dr Ian Forbes of IOP Publishing for managing the entire process and to the editorial staff of Journal of Micromechanics and Microengineering. I trust that this special issue will provide new trends of the emerging field of micro system technology and I hope you enjoy reading it.

The subtyping of primary aldosteronism by adrenal vein sampling: sequential blood sampling causes factitious lateralization.

PubMed

Rossitto, Giacomo; Battistel, Michele; Barbiero, Giulio; Bisogni, Valeria; Maiolino, Giuseppe; Diego, Miotto; Seccia, Teresa M; Rossi, Gian Paolo

2018-02-01

The pulsatile secretion of adrenocortical hormones and a stress reaction occurring when starting adrenal vein sampling (AVS) can affect the selectivity and also the assessment of lateralization when sequential blood sampling is used. We therefore tested the hypothesis that a simulated sequential blood sampling could decrease the diagnostic accuracy of lateralization index for identification of aldosterone-producing adenoma (APA), as compared with bilaterally simultaneous AVS. In 138 consecutive patients who underwent subtyping of primary aldosteronism, we compared the results obtained simultaneously bilaterally when starting AVS (t-15) and 15 min after (t0), with those gained with a simulated sequential right-to-left AVS technique (R ⇒ L) created by combining hormonal values obtained at t-15 and at t0. The concordance between simultaneously obtained values at t-15 and t0, and between simultaneously obtained values and values gained with a sequential R ⇒ L technique, was also assessed. We found a marked interindividual variability of lateralization index values in the patients with bilaterally selective AVS at both time point. However, overall the lateralization index simultaneously determined at t0 provided a more accurate identification of APA than the simulated sequential lateralization indexR ⇒ L (P = 0.001). Moreover, regardless of which side was sampled first, the sequential AVS technique induced a sequence-dependent overestimation of lateralization index. While in APA patients the concordance between simultaneous AVS at t0 and t-15 and between simultaneous t0 and sequential technique was moderate-to-good (K = 0.55 and 0.66, respectively), in non-APA patients, it was poor (K = 0.12 and 0.13, respectively). Sequential AVS generates factitious between-sides gradients, which lower its diagnostic accuracy, likely because of the stress reaction arising upon starting AVS.

The Nature of Phonological Encoding During Spoken Word Retrieval.

ERIC Educational Resources Information Center

Sullivan, Michael P.; Riffel, Brian

1999-01-01

Examined whether phonological selection occurs sequentially or in parallel. College students named picture primes and targets, with varied response stimulus intervals between primes and targets. Results were consistent with Dell's (1988) two-stage sequential model of encoding, which shows an initial parallel activation within a lexical network…

EDITORIAL: Selected papers from the 20th Micromechanics Europe Workshop (MME 09) (Toulouse, France, 20-22 September 2009) Selected papers from the 20th Micromechanics Europe Workshop (MME 09) (Toulouse, France, 20-22 September 2009)

NASA Astrophysics Data System (ADS)

Pons, Patrick

2010-06-01

This special section of the Journal of Micromechanics and Microengineering is devoted to the 20th European Workshop on Micromechanics (MME 2009), which was held in Toulouse, France, 20-22 September 2009. The MME workshop series started in 1989 in Twente and was the first European event created in the field of micro machining technology for developing micro components, micro sensors, micro actuators, and micro systems. Over the last two decades the MEMS community has grown considerably, and the MME workshops have sustained this progress through annual meetings all around Europe: Twente (The Netherlands, 1989), Berlin (Germany, 1990), Leuven (Belgium, 1992), Neuchatel (Switzerland, 1993), Pisa (Italy, 1994), Copenhagen (Denmark, 1995), Barcelona (Spain, 1996), Southampton (United Kingdom, 1997), Ulvik (Norway, 1998), Gif-sur-Yvette (France, 1999), Uppsala (Sweden, 2000), Cork (Ireland, 2001), Sinaia (Romania, 2002), Delft (The Netherlands, 2003), Leuven (Belgium, 2004), Goteborg (Sweden, 2005), Southampton (United Kingdom, 2006), Guimaraes (Portugal, 2007) and Aachen (Germany, 2008). For twenty years, MME conferences have provided an excellent opportunity to bring together many, predominantly European, scientists and engineers to present and discuss the latest developments in this field. For the 20th anniversary of the MicroMechanics Europe Workshop, 115 papers from 23 countries were submitted. Selected contributions were presented during four poster sessions, including short oral presentations. A very interesting feature of the MME workshops is their ability to promote young researchers. Six invited speakers from research centres and industry also gave an overview on advanced technological, characterization and simulation tools. The two day workshop was attended by 185 delegates from 22 countries all over Europe, and from Japan, Taiwan, USA and Mexico. On behalf of the MME 2009 Program Committee, I would like to express my sincere gratitude to all authors of submitted papers. Their high levels of quality and considerable quantity serve as the foundation of this workshop's success. I'm also grateful to all the Program Committee members (Professor Miko Elwenspoek, Dr Martin Hill and Dr Uwe Schnakenberg) who gave their valuable time to review these numerous papers. I am proud to present 20 high-quality papers from MME 2009, selected through the regular review procedure of IOP Publishing, for their novelty and relevance to Journal of Micromechanics and Microengineering. These papers give a good overview of the topics presented during the workshop (microtechnology, characterization, sensors and actuators). I would also like to express my gratitude to Professor Robert Puers for advising on paper selection and to Dr Ian Forbes for coordinating this special section with the IOP Publishing office. I hope you enjoy reading this selection of papers.

Discrimination between sequential and simultaneous virtual channels with electrical hearing

PubMed Central

Landsberger, David; Galvin, John J.

2011-01-01

In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation modes. For sequential VCs, the interpulse interval (IPI) varied between 0.0 and 1.8 ms. All stimuli were presented at comfortably loud, loudness-balanced levels at a 250 pulse per second per electrode (ppse) stimulation rate. On average, CI subjects were able to reliably discriminate between sequential and simultaneous VCs. While there was no significant effect of IPI or stimulation mode on VC discrimination, some subjects exhibited better VC discrimination with BP + 1 stimulation. Subjects’ discrimination between sequential and simultaneous VCs was correlated with electrode discrimination, suggesting that spatial selectivity may influence perception of sequential VCs. To maintain equal loudness, sequential VC amplitudes were nearly double those of simultaneous VCs, presumably resulting in a broader spread of excitation. These results suggest that perceptual differences between simultaneous and sequential VCs might be explained by differences in the spread of excitation. PMID:21895094

Discrimination between sequential and simultaneous virtual channels with electrical hearing.

PubMed

Landsberger, David; Galvin, John J

2011-09-01

In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation modes. For sequential VCs, the interpulse interval (IPI) varied between 0.0 and 1.8 ms. All stimuli were presented at comfortably loud, loudness-balanced levels at a 250 pulse per second per electrode (ppse) stimulation rate. On average, CI subjects were able to reliably discriminate between sequential and simultaneous VCs. While there was no significant effect of IPI or stimulation mode on VC discrimination, some subjects exhibited better VC discrimination with BP + 1 stimulation. Subjects' discrimination between sequential and simultaneous VCs was correlated with electrode discrimination, suggesting that spatial selectivity may influence perception of sequential VCs. To maintain equal loudness, sequential VC amplitudes were nearly double those of simultaneous VCs, presumably resulting in a broader spread of excitation. These results suggest that perceptual differences between simultaneous and sequential VCs might be explained by differences in the spread of excitation. © 2011 Acoustical Society of America

Fabrication of a co-culture micro-bioreactor device for efficient hepatic differentiation of human induced pluripotent stem cells (hiPSCs).

PubMed

Kehtari, Mousa; Zeynali, Bahman; Soleimani, Masoud; Kabiri, Mahboubeh; Seyedjafari, Ehsan

2018-04-27

Primary hepatocytes, as the gold standard cell type for in vitro models, lose their characteristic morphology and functions after few days. There is an urgent need to develop physiologically relevant models that recapitulate liver microenvironment to obtain mature hepatocyte from stem cells. We designed and fabricated a micro-bioreactor device mimicking the physiological shear stress and cell-cell interaction in liver sinusoid microenvironment. Induced pluripotent stem cells (iPSCs) were co-cultured with human umbilical vein endothelial cells (HUVECs) in the micro-bioreactor device with continuous perfusion of hepatic differentiation medium (100 μL/h). Simulation results showed that flow field inside our perfusion device was uniform and shear stress was adjusted to physiological condition (<2 dyne/cm 2 ). IPSCs-derived hepatocytes (iPSCs-Heps) that were cultured in micro-bioreactor device showed a higher level of hepatic markers compared to those in static condition. Flow cytometry and immunocytochemistry analysis revealed iPSCs cultured in the device sequentially acquired characteristics of definitive endodermal cells (SOX17 positive), hepatoblasts (AFP positive) and mature hepatocyte (ALB positive). Moreover, the albumin and urea secretion were significantly higher in micro-bioreactor device than those cultured in culture dishes during experiment. Thus, based on our results, we propose our micro-bioreactor as a beneficial device to generate mature hepatocytes for drug screening and basic research.

Microcomputer-based artificial vision support system for real-time image processing for camera-driven visual prostheses.

PubMed

Fink, Wolfgang; You, Cindy X; Tarbell, Mark A

2010-01-01

It is difficult to predict exactly what blind subjects with camera-driven visual prostheses (e.g., retinal implants) can perceive. Thus, it is prudent to offer them a wide variety of image processing filters and the capability to engage these filters repeatedly in any user-defined order to enhance their visual perception. To attain true portability, we employ a commercial off-the-shelf battery-powered general purpose Linux microprocessor platform to create the microcomputer-based artificial vision support system (microAVS(2)) for real-time image processing. Truly standalone, microAVS(2) is smaller than a deck of playing cards, lightweight, fast, and equipped with USB, RS-232 and Ethernet interfaces. Image processing filters on microAVS(2) operate in a user-defined linear sequential-loop fashion, resulting in vastly reduced memory and CPU requirements during execution. MiccroAVS(2) imports raw video frames from a USB or IP camera, performs image processing, and issues the processed data over an outbound Internet TCP/IP or RS-232 connection to the visual prosthesis system. Hence, microAVS(2) affords users of current and future visual prostheses independent mobility and the capability to customize the visual perception generated. Additionally, microAVS(2) can easily be reconfigured for other prosthetic systems. Testing of microAVS(2) with actual retinal implant carriers is envisioned in the near future.

Shape-morphing composites with designed micro-architectures

NASA Astrophysics Data System (ADS)

Rodriguez, Jennifer N.; Zhu, Cheng; Duoss, Eric B.; Wilson, Thomas S.; Spadaccini, Christopher M.; Lewicki, James P.

2016-06-01

Shape memory polymers (SMPs) are attractive materials due to their unique mechanical properties, including high deformation capacity and shape recovery. SMPs are easier to process, lightweight, and inexpensive compared to their metallic counterparts, shape memory alloys. However, SMPs are limited to relatively small form factors due to their low recovery stresses. Lightweight, micro-architected composite SMPs may overcome these size limitations and offer the ability to combine functional properties (e.g., electrical conductivity) with shape memory behavior. Fabrication of 3D SMP thermoset structures via traditional manufacturing methods is challenging, especially for designs that are composed of multiple materials within porous microarchitectures designed for specific shape change strategies, e.g. sequential shape recovery. We report thermoset SMP composite inks containing some materials from renewable resources that can be 3D printed into complex, multi-material architectures that exhibit programmable shape changes with temperature and time. Through addition of fiber-based fillers, we demonstrate printing of electrically conductive SMPs where multiple shape states may induce functional changes in a device and that shape changes can be actuated via heating of printed composites. The ability of SMPs to recover their original shapes will be advantageous for a broad range of applications, including medical, aerospace, and robotic devices.

Reproducible Tissue Homogenization and Protein Extraction for Quantitative Proteomics Using MicroPestle-Assisted Pressure-Cycling Technology.

PubMed

Shao, Shiying; Guo, Tiannan; Gross, Vera; Lazarev, Alexander; Koh, Ching Chiek; Gillessen, Silke; Joerger, Markus; Jochum, Wolfram; Aebersold, Ruedi

2016-06-03

The reproducible and efficient extraction of proteins from biopsy samples for quantitative analysis is a critical step in biomarker and translational research. Recently, we described a method consisting of pressure-cycling technology (PCT) and sequential windowed acquisition of all theoretical fragment ions-mass spectrometry (SWATH-MS) for the rapid quantification of thousands of proteins from biopsy-size tissue samples. As an improvement of the method, we have incorporated the PCT-MicroPestle into the PCT-SWATH workflow. The PCT-MicroPestle is a novel, miniaturized, disposable mechanical tissue homogenizer that fits directly into the microTube sample container. We optimized the pressure-cycling conditions for tissue lysis with the PCT-MicroPestle and benchmarked the performance of the system against the conventional PCT-MicroCap method using mouse liver, heart, brain, and human kidney tissues as test samples. The data indicate that the digestion of the PCT-MicroPestle-extracted proteins yielded 20-40% more MS-ready peptide mass from all tissues tested with a comparable reproducibility when compared to the conventional PCT method. Subsequent SWATH-MS analysis identified a higher number of biologically informative proteins from a given sample. In conclusion, we have developed a new device that can be seamlessly integrated into the PCT-SWATH workflow, leading to increased sample throughput and improved reproducibility at both the protein extraction and proteomic analysis levels when applied to the quantitative proteomic analysis of biopsy-level samples.

The effect of flavonol glycosides on opiate withdrawal.

PubMed

Capasso, Anna

2007-07-01

Our interest has been centered on flavonol glycosides from Croton Menthodorus (Euphorbiaceae) and Aristeguietia discolor (Asteraceae). In this respect, the effect of flavonol glycosides from Croton Menthodorus (Euphorbiaceae) and Aristeguietia discolor (Asteraceae) was investigated on the naloxone-precipitated withdrawal contracture of the acute morphine-dependent guinea-pig ileum in vitro. Furthermore, the effect of these flavonol glycosides was also considered on DAGO (highly selective micro-agonist) and U50-488H (highly selective k-agonist) withdrawal to test whether the possible interaction of flavonol glycosides on opioid withdrawal involves micro- and/or k-opioid receptors. Flavonol glycosides from Croton Menthodorus (1 x 10(-5), 5 x 10(-5) and 1 x 10(-4) M) and from Aristeguietia discolor (1 x 10(-7)-1 x 10(-6)-1 x 10(-5) M) before or after the opioid agonists were able to both prevent and reverse the naloxone-induced contracture after exposure to micro (morphine and DAGO) or k (U50-488H) opiate agonists in a concentration-dependent fashion. Both acetylcholine response and electrical stimulation were reduced by flavonol glycosides treatment as well as the final opiate withdrawal was still reduced. The results of the present study indicate that flavonol glycosides were able to produce significant influence on the opiate withdrawal in vitro and these compounds were able to exert their effects both at micro and k opioid agonists.

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

PubMed Central

Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole

2016-01-01

The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles. PMID:26917133

MicroCT angiography detects vascular formation and regression in skin wound healing

PubMed Central

Urao, Norifumi; Okonkwo, Uzoagu A.; Fang, Milie M.; Zhuang, Zhen W.; Koh, Timothy J.; DiPietro, Luisa A.

2016-01-01

Properly regulated angiogenesis and arteriogenesis are essential for effective wound healing. Tissue injury induces robust new vessel formation and subsequent vessel maturation, which involves vessel regression and remodeling. Although formation of functional vasculature is essential for healing, alterations in vascular structure over the time course of skin wound healing are not well understood. Here, using high-resolution ex vivo X-ray micro-computed tomography (microCT), we describe the vascular network during healing of skin excisional wounds with highly detailed three-dimensional (3D) reconstructed images and associated quantitative analysis. We found that relative vessel volume, surface area and branching number are significantly decreased in wounds from day 7 to day 14 and 21. Segmentation and skeletonization analysis of selected branches from high-resolution images as small as 2.5 μm voxel size show that branching orders are decreased in the wound vessels during healing. In histological analysis, we found that the contrast agent fills mainly arterioles, but not small capillaries nor large veins. In summary, high-resolution microCT revealed dynamic alterations of vessel structures during wound healing. This technique may be useful as a key tool in the study of the formation and regression of wound vessels. PMID:27009591

Isolation and Characterization of a microRNA-size Secretable Small RNA in Streptococcus sanguinis.

PubMed

Choi, Ji-Woong; Kwon, Tae-Yub; Hong, Su-Hyung; Lee, Heon-Jin

2018-06-01

MicroRNAs in eukaryotic cells are thought to control highly complex signal transduction and other biological processes by regulating coding transcripts, accounting for their important role in cellular events in eukaryotes. Recently, a novel class of bacterial RNAs similar in size [18-22 nucleotides (nt)] to microRNAs has been reported. Herein, we describe microRNAs, small RNAs from the oral pathogen Streptococcus sanguinis. The bacteria are normally present in the oral cavities and cause endocarditis by contaminating bloodstreams. Small RNAs were analyzed by deep sequencing. Selected highly expressed small RNAs were further validated by real-time polymerase chain reaction and northern blot analyses. We found that skim milk supplement changed the expression of small RNAs S.S-1964 in tandem with the nearby SSA_0513 gene involved in vitamin B 12 conversion. We furthermore observed small RNAs secreted via bacterial membrane vesicles. Although their precise function remains unclear, secretable small RNAs may represent an entirely new area of study in bacterial genetics.

Role of selective cyclic GMP phosphodiesterase inhibition in the myorelaxant actions of M&B 22,948, MY-5445, vinpocetine and 1-methyl-3-isobutyl-8-(methylamino)xanthine.

PubMed Central

Souness, J. E.; Brazdil, R.; Diocee, B. K.; Jordan, R.

1989-01-01

1. The mechanism by which M&B 22,948, MY-5445, vinpocetine and 1-methyl-3-isobutyl-8-(methylamino)xanthine (MIMAX), which have been described as selective cyclic GMP phosphodiesterase (PDE) inhibitors, relax rat aorta was investigated. 2. Three cyclic nucleotide PDEs were identified in the soluble fraction of rat aorta; a Ca2+-insensitive form exhibiting substrate selectivity for cyclic GMP (cGMP PDE), a Ca2+/calmodulin-stimulated form which also preferentially hydrolyzed cyclic GMP (Ca2+ PDE), and a form demonstrating substrate selectivity for cyclic AMP (cAMP PDE). 3. M&B 22,948 and MIMAX inhibited cGMP PDE (Ki = 0.16 microM and 0.43 microM, respectively) and Ca2+ PDE (Ki = 9.9 microM and 0.55 microM, respectively), but exhibited weak activity against cAMP PDE (Ki = 249 microM and 42 microM, respectively). MY-5445 selectivity inhibited cGMP PDE (Ki = 1.3 microM) and vinpocetine selectively inhibited Ca2+ PDE (Ki = 14 microM). 4. M&B 22,948 and MIMAX induced dose-dependent increases in the accumulation of cyclic GMP, but not cyclic AMP, in rat aorta pieces. These effects were greatly reduced by endothelial denudation and by methylene blue (5 microM) which blocks the actions of endothelium-derived relaxant factor. MY-5445 and vinpocetine had no effect on rat aorta cyclic GMP or cyclic AMP accumulation. 5. All four compounds caused dose-related relaxation of 5-hydroxytryptamine (10 microM) contracted, endothelium-intact rat aorta, the effects of M&B 22,948 and MIMAX being greatly reduced by methylene blue (5 microM). Methylene blue also caused 10 fold and 100 fold rightward shifts in the dose-response curves of MY-5445 and vinpocetine, respectively. 6. The results are consistent with the smooth muscle relaxant actions of M&B 22,948 and MIMAX, but not vinpocetine and MY-5445, being mediated through a mechanism involving inhibition of cyclic GMP hydrolysis. PMID:2480168

Application of micro X-ray diffraction to investigate the reaction products formed by the alkali silica reaction in concrete structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dähn, R.; Arakcheeva, A.; Schaub, Ph.

Alkali–silica reaction (ASR) is one of the most important deterioration mechanisms in concrete leading to substantial damages of structures worldwide. Synchrotron-based micro-X-ray diffraction (micro-XRD) was employed to characterize the mineral phases formed in micro-cracks of concrete aggregates as a consequence of ASR. This particular high spatial resolution technique enables to directly gain structural information on ASR products formed in a 40-year old motorway bridge damaged due to ASR. Micro-X-ray-fluorescence was applied on thin sections to locate the reaction products formed in veins within concrete aggregates. Micro-XRD pattern were collected at selected points of interest along a vein by rotating themore » sample. Rietveld refinement determined the structure of the ASR product consisting of a new layered framework similar to mountainite and rhodesite. Furthermore, it is conceivable that understanding the structure of the ASR product may help developing new technical treatments inhibiting ASR.« less

Application of micro X-ray diffraction to investigate the reaction products formed by the alkali–silica reaction in concrete structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dähn, R., E-mail: rainer.daehn@psi.ch; Arakcheeva, A.; Schaub, Ph.

Alkali–silica reaction (ASR) is one of the most important deterioration mechanisms in concrete leading to substantial damages of structures worldwide. Synchrotron-based micro-X-ray diffraction (micro-XRD) was employed to characterize the mineral phases formed in micro-cracks of concrete aggregates as a consequence of ASR. This high spatial resolution technique enables to directly gain structural information on ASR products formed in a 40-year old motorway bridge damaged due to ASR. Micro-X-ray-fluorescence was applied on thin sections to locate the reaction products formed in veins within concrete aggregates. Micro-XRD pattern were collected at selected points of interest along a vein by rotating the sample.more » Rietveld refinement determined the structure of the ASR product consisting of a new layered framework similar to mountainite and rhodesite. It is conceivable that understanding the structure of the ASR product may help developing new technical treatments inhibiting ASR.« less

Electromagnetic characterization of photo-definable ferrite loaded polymers and their applications in micro-rectangular coaxial phase shifters

NASA Astrophysics Data System (ADS)

Sholiyi, Olusegun Samuel

As the demand for smaller size, lighter weight, lower loss and cost of communications transmit and receive (T/R) modules increases, there is an urgent need to focus investigation to the major subsystem or components that can improve these parameters. Phase shifters contribute greatly to the cost of T/R modules, and thus this research investigation examines a new way to reduce the weight and cost by miniaturizing the phaser design. Characterization of hexaferrite powders compatible with the sequential multilayer micro-fabrication technology and numerical simulations of a novel rectangular micro-coaxial phase shifter are investigated. This effort aims to integrate ferrite material into a rectangular micro-coaxial waveguide at Ka-band using electromagnetic finite element numerical tools. The proposed technique exploits rectangular coaxial waveguide with a symmetrically placed inner signal conductor inside an outer conductor connected to the ground. Strontium ferrite-SU8 composite is used as an anisotropic material of choice in the modelled design. Numerical modeling is employed using High Frequency Structure Simulator, HFSS, a 3-D full wave electromagnetic solver for analyzing the performance of the device. Two model structures were designed for reciprocal and non-reciprocal applications. The first model (Model A) produced a tunable phase shift of almost 60 degrees /cm across 0 to 400 kA/m applied field and at 1800 Gauss. In model B, a non-reciprocal phase shift performance of 20 degrees /cm from a reference phase of 24 degrees at 0 A/m was realized at the same saturation magnetization. A return loss better than 20 dB and an insertion loss less than 1.5 dB were obtained for both models.

Hormonal regulation of Drosophila microRNA let-7 and miR-125 that target innate immunity.

PubMed

Garbuzov, Alina; Tatar, Marc

2010-01-01

The steroid 20-hydroxy-ecdysone (20-HE) and the sesquiterpenoid Juvenile Hormone (JH) coordinate insect life stage transitions. 20-HE exerts these effects by the sequential induction of response genes. In the nematode Caenorhabditis elegans hormones also play a role in such transitions, but notably, microRNA such as let-7 and lin-4 have likewise been found to help order developmental steps. Little is known about the corresponding function of homologous microRNA in Drosophila melanogaster, and the way microRNA might be regulated by 20-HE in the fly is ambiguous. Here we used Drosophila S2 cells to analyze the effects of 20-HE on D. melanogaster microRNA let-7 and miR-125, the homolog of lin-4. The induction by 20-HE of let-7 and miR-125 in S2 cells is inhibited by RNAi knockdown of the ecdysone receptor and, as previously shown, by knockdown of its cofactor broad-complex C. To help resolve the currently ambiguous role of 20-HE in the control of microRNA, we show that nanomolar concentrations of 20-HE primes cells to subsequently express microRNA when exposed to micromolar levels of 20-HE. We then explore the role microRNA plays in the established relationship between 20-HE and the induction of innate immunity. We show that the 3'UTR of the antimicrobial peptide diptericin has a let-7 binding site and that let-7 represses translation from this site. We conclude that 20-HE facilitates the initial expression of innate immunity while it simultaneously induces negative regulation via microRNA control of antimicrobial peptide translation.

Non-canonical microRNAs miR-320 and miR-702 promote proliferation in Dgcr8-deficient embryonic stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Byeong-Moo; Department of Medicine, Harvard Medical School, Boston, MA 02115; Choi, Michael Y., E-mail: mchoi@partners.org

2012-09-21

Highlights: Black-Right-Pointing-Pointer Embryonic stem cells (ESCs) lacking non-canonical miRNAs proliferate slower. Black-Right-Pointing-Pointer miR-320 and miR-702 are two non-canonical miRNAs expressed in ESCs. Black-Right-Pointing-Pointer miR-320 and miR-702 promote proliferation of Dgcr8-deficient ESCs. Black-Right-Pointing-Pointer miR-320 targets p57 and helps to release Dgcr8-deficient ESCs from G1 arrest. Black-Right-Pointing-Pointer miR-702 targets p21 and helps to release Dgcr8-deficient ESCs from G1 arrest. -- Abstract: MicroRNAs are known to contribute significantly to stem cell phenotype by post-transcriptionally regulating gene expression. Most of our knowledge of microRNAs comes from the study of canonical microRNAs that require two sequential cleavages by the Drosha/Dgcr8 heterodimer and Dicer to generatemore » mature products. In contrast, non-canonical microRNAs bypass the cleavage by the Drosha/Dgcr8 heterodimer within the nucleus but still require cytoplasmic cleavage by Dicer. The function of non-canonical microRNAs in embryonic stem cells (ESCs) remains obscure. It has been hypothesized that non-canonical microRNAs have important roles in ESCs based upon the phenotypes of ESC lines that lack these specific classes of microRNAs; Dicer-deficient ESCs lacking both canonical and non-canonical microRNAs have much more severe proliferation defect than Dgcr8-deficient ESCs lacking only canonical microRNAs. Using these cell lines, we identified two non-canonical microRNAs, miR-320 and miR-702, that promote proliferation of Dgcr8-deficient ESCs by releasing them from G1 arrest. This is accomplished by targeting the 3 Prime -untranslated regions of the cell cycle inhibitors p57 and p21 and thereby inhibiting their expression. This is the first report of the crucial role of non-canonical microRNAs in ESCs.« less

Instant Integrated Ultradeep Quantitative-structural Membrane Proteomics Discovered Post-translational Modification Signatures for Human Cys-loop Receptor Subunit Bias*

PubMed Central

Zhang, Xi

2016-01-01

Neurotransmitter ligand-gated ion channels (LGICs) are widespread and pivotal in brain functions. Unveiling their structure-function mechanisms is crucial to drive drug discovery, and demands robust proteomic quantitation of expression, post-translational modifications (PTMs) and dynamic structures. Yet unbiased digestion of these modified transmembrane proteins—at high efficiency and peptide reproducibility—poses the obstacle. Targeting both enzyme-substrate contacts and PTMs for peptide formation and detection, we devised flow-and-detergent-facilitated protease and de-PTM digestions for deep sequencing (FDD) method that combined omni-compatible detergent, tandem immobilized protease/PNGase columns, and Cys-selective reduction/alkylation, to achieve streamlined ultradeep peptide preparation within minutes not days, at high peptide reproducibility and low abundance-bias. FDD transformed enzyme-protein contacts into equal catalytic travel paths through enzyme-excessive columns regardless of protein abundance, removed products instantly preventing inhibition, tackled intricate structures via sequential multiple micro-digestions along the flow, and precisely controlled peptide formation by flow rate. Peptide-stage reactions reduced steric bias; low contamination deepened MS/MS scan; distinguishing disulfide from M oxidation and avoiding gain/loss artifacts unmasked protein-endogenous oxidation states. Using a recent interactome of 285-kDa human GABA type A receptor, this pilot study validated FDD platform's applicability to deep sequencing (up to 99% coverage), H/D-exchange and TMT-based structural mapping. FDD discovered novel subunit-specific PTM signatures, including unusual nontop-surface N-glycosylations, that may drive subunit biases in human Cys-loop LGIC assembly and pharmacology, by redefining subunit/ligand interfaces and connecting function domains. PMID:27073180

A GPU-Based Implementation of the Firefly Algorithm for Variable Selection in Multivariate Calibration Problems

PubMed Central

de Paula, Lauro C. M.; Soares, Anderson S.; de Lima, Telma W.; Delbem, Alexandre C. B.; Coelho, Clarimar J.; Filho, Arlindo R. G.

2014-01-01

Several variable selection algorithms in multivariate calibration can be accelerated using Graphics Processing Units (GPU). Among these algorithms, the Firefly Algorithm (FA) is a recent proposed metaheuristic that may be used for variable selection. This paper presents a GPU-based FA (FA-MLR) with multiobjective formulation for variable selection in multivariate calibration problems and compares it with some traditional sequential algorithms in the literature. The advantage of the proposed implementation is demonstrated in an example involving a relatively large number of variables. The results showed that the FA-MLR, in comparison with the traditional algorithms is a more suitable choice and a relevant contribution for the variable selection problem. Additionally, the results also demonstrated that the FA-MLR performed in a GPU can be five times faster than its sequential implementation. PMID:25493625

A GPU-Based Implementation of the Firefly Algorithm for Variable Selection in Multivariate Calibration Problems.

PubMed

de Paula, Lauro C M; Soares, Anderson S; de Lima, Telma W; Delbem, Alexandre C B; Coelho, Clarimar J; Filho, Arlindo R G

2014-01-01

Several variable selection algorithms in multivariate calibration can be accelerated using Graphics Processing Units (GPU). Among these algorithms, the Firefly Algorithm (FA) is a recent proposed metaheuristic that may be used for variable selection. This paper presents a GPU-based FA (FA-MLR) with multiobjective formulation for variable selection in multivariate calibration problems and compares it with some traditional sequential algorithms in the literature. The advantage of the proposed implementation is demonstrated in an example involving a relatively large number of variables. The results showed that the FA-MLR, in comparison with the traditional algorithms is a more suitable choice and a relevant contribution for the variable selection problem. Additionally, the results also demonstrated that the FA-MLR performed in a GPU can be five times faster than its sequential implementation.

Two multichannel integrated circuits for neural recording and signal processing.

PubMed

Obeid, Iyad; Morizio, James C; Moxon, Karen A; Nicolelis, Miguel A L; Wolf, Patrick D

2003-02-01

We have developed, manufactured, and tested two analog CMOS integrated circuit "neurochips" for recording from arrays of densely packed neural electrodes. Device A is a 16-channel buffer consisting of parallel noninverting amplifiers with a gain of 2 V/V. Device B is a 16-channel two-stage analog signal processor with differential amplification and high-pass filtering. It features selectable gains of 250 and 500 V/V as well as reference channel selection. The resulting amplifiers on Device A had a mean gain of 1.99 V/V with an equivalent input noise of 10 microV(rms). Those on Device B had mean gains of 53.4 and 47.4 dB with a high-pass filter pole at 211 Hz and an equivalent input noise of 4.4 microV(rms). Both devices were tested in vivo with electrode arrays implanted in the somatosensory cortex.

Cathodoluminescence microscopy and spectroscopy of micro- and nanodiamonds: an implication for laboratory astrophysics.

PubMed

Gucsik, Arnold; Nishido, Hirotsugu; Ninagawa, Kiyotaka; Ott, Ulrich; Tsuchiyama, Akira; Kayama, Masahiro; Simonia, Irakli; Boudou, Jean-Paul

2012-12-01

Color centers in selected micro- and nanodiamond samples were investigated by cathodoluminescence (CL) microscopy and spectroscopy at 298 K [room temperature (RT)] and 77 K [liquid-nitrogen temperature (LNT)] to assess the value of the technique for astrophysics. Nanodiamonds from meteorites were compared with synthetic diamonds made with different processes involving distinct synthesis mechanisms (chemical vapor deposition, static high pressure high temperature, detonation). A CL emission peak centered at around 540 nm at 77 K was observed in almost all of the selected diamond samples and is assigned to the dislocation defect with nitrogen atoms. Additional peaks were identified at 387 and 452 nm, which are related to the vacancy defect. In general, peak intensity at LNT at the samples was increased in comparison to RT. The results indicate a clear temperature-dependence of the spectroscopic properties of diamond. This suggests the method is a useful tool in laboratory astrophysics.

Automated Proton Track Identification in MicroBooNE Using Gradient Boosted Decision Trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodruff, Katherine

MicroBooNE is a liquid argon time projection chamber (LArTPC) neutrino experiment that is currently running in the Booster Neutrino Beam at Fermilab. LArTPC technology allows for high-resolution, three-dimensional representations of neutrino interactions. A wide variety of software tools for automated reconstruction and selection of particle tracks in LArTPCs are actively being developed. Short, isolated proton tracks, the signal for low- momentum-transfer neutral current (NC) elastic events, are easily hidden in a large cosmic background. Detecting these low-energy tracks will allow us to probe interesting regions of the proton's spin structure. An effective method for selecting NC elastic events is tomore » combine a highly efficient track reconstruction algorithm to find all candidate tracks with highly accurate particle identification using a machine learning algorithm. We present our work on particle track classification using gradient tree boosting software (XGBoost) and the performance on simulated neutrino data.« less

Solar Radiation-Associated Adaptive SNP Genetic Differentiation in Wild Emmer Wheat, Triticum dicoccoides.

PubMed

Ren, Jing; Chen, Liang; Jin, Xiaoli; Zhang, Miaomiao; You, Frank M; Wang, Jirui; Frenkel, Vladimir; Yin, Xuegui; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

2017-01-01

Whole-genome scans with large number of genetic markers provide the opportunity to investigate local adaptation in natural populations and identify candidate genes under positive selection. In the present study, adaptation genetic differentiation associated with solar radiation was investigated using 695 polymorphic SNP markers in wild emmer wheat originated in a micro-site at Yehudiyya, Israel. The test involved two solar radiation niches: (1) sun, in-between trees; and (2) shade, under tree canopy, separated apart by a distance of 2-4 m. Analysis of molecular variance showed a small (0.53%) but significant portion of overall variation between the sun and shade micro-niches, indicating a non-ignorable genetic differentiation between sun and shade habitats. Fifty SNP markers showed a medium (0.05 ≤ F ST ≤ 0.15) or high genetic differentiation ( F ST > 0.15). A total of 21 outlier loci under positive selection were identified by using four different F ST -outlier testing algorithms. The markers and genome locations under positive selection are consistent with the known patterns of selection. These results suggested that genetic differentiation between sun and shade habitats is substantial, radiation-associated, and therefore ecologically determined. Hence, the results of this study reflected effects of natural selection through solar radiation on EST-related SNP genetic diversity, resulting presumably in different adaptive complexes at a micro-scale divergence. The present work highlights the evolutionary theory and application significance of solar radiation-driven natural selection in wheat improvement.

Real-time 2D spatially selective MRI experiments: Comparative analysis of optimal control design methods

NASA Astrophysics Data System (ADS)

Maximov, Ivan I.; Vinding, Mads S.; Tse, Desmond H. Y.; Nielsen, Niels Chr.; Shah, N. Jon

2015-05-01

There is an increasing need for development of advanced radio-frequency (RF) pulse techniques in modern magnetic resonance imaging (MRI) systems driven by recent advancements in ultra-high magnetic field systems, new parallel transmit/receive coil designs, and accessible powerful computational facilities. 2D spatially selective RF pulses are an example of advanced pulses that have many applications of clinical relevance, e.g., reduced field of view imaging, and MR spectroscopy. The 2D spatially selective RF pulses are mostly generated and optimised with numerical methods that can handle vast controls and multiple constraints. With this study we aim at demonstrating that numerical, optimal control (OC) algorithms are efficient for the design of 2D spatially selective MRI experiments, when robustness towards e.g. field inhomogeneity is in focus. We have chosen three popular OC algorithms; two which are gradient-based, concurrent methods using first- and second-order derivatives, respectively; and a third that belongs to the sequential, monotonically convergent family. We used two experimental models: a water phantom, and an in vivo human head. Taking into consideration the challenging experimental setup, our analysis suggests the use of the sequential, monotonic approach and the second-order gradient-based approach as computational speed, experimental robustness, and image quality is key. All algorithms used in this work were implemented in the MATLAB environment and are freely available to the MRI community.

A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater

PubMed Central

Yang, Ruihong; ZHU, Jianzhong; Li, Yingliu; Zhang, Hui

2016-01-01

Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na2SO4 additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography–mass spectrometry (GC–MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet–visible spectroscopy (UV–VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency. PMID:27136574

A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater.

PubMed

Yang, Ruihong; Zhu, Jianzhong; Li, Yingliu; Zhang, Hui

2016-04-29

Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na₂SO₄ additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography-mass spectrometry (GC-MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet-visible spectroscopy (UV-VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency.

Combat Identification with Sequential Observations, Rejection Option, and Out-of-Library Targets

DTIC Science & Technology

2005-09-01

nature of the entities sharing the battlespace is unknown. Here CID characterizes those entities using information from a variety of sources. The goal...producing high-resolution returns with signif - icantly enhanced target to clutter (and noise) ratios through Doppler filtering and clutter...treat the subject from a natural science perspective. The following 43 subsections on the various model selection techniques are derived from these

Cost-effectiveness of simultaneous versus sequential surgery in head and neck reconstruction.

PubMed

Wong, Kevin K; Enepekides, Danny J; Higgins, Kevin M

2011-02-01

To determine whether simultaneous (ablation and reconstruction overlaps by two teams) head and neck reconstruction is cost effective compared to sequentially (ablation followed by reconstruction) performed surgery. Case-controlled study. Tertiary care hospital. Oncology patients undergoing free flap reconstruction of the head and neck. A match paired comparison study was performed with a retrospective chart review examining the total time of surgery for sequential and simultaneous surgery. Nine patients were selected for both the sequential and simultaneous groups. Sequential head and neck reconstruction patients were pair matched with patients who had undergone similar oncologic ablative or reconstructive procedures performed in a simultaneous fashion. A detailed cost analysis using the microcosting method was then undertaken looking at the direct costs of the surgeons, anesthesiologist, operating room, and nursing. On average, simultaneous surgery required 3 hours 15 minutes less operating time, leading to a cost savings of approximately $1200/case when compared to sequential surgery. This represents approximately a 15% reduction in the cost of the entire operation. Simultaneous head and neck reconstruction is more cost effective when compared to sequential surgery.

DOE Office of Scientific and Technical Information (OSTI.GOV)

RF Kristensen; JF Beausang; DM DePoy

Frequency selective surfaces (FSS) effectively filter electromagnetic radiation in the microwave band (1 mm to 100 mm). Interest exists in extending this technology to the near infrared (1 {micro}m to 10 {micro}m) for use as a filter of thermal radiation in thermophotovoltaic (TPV) direct energy conversion. This paper assesses the ability of FSS to meet the strict spectral performance requirements of a TPV system. Inherent parasitic absorption, which is the result of the induced currents in the FSS metallization, is identified as a significant obstacle to achieving high spectral performance.

Micro-tubular solid oxide fuel cell based on a porous yttria-stabilized zirconia support

NASA Astrophysics Data System (ADS)

Panthi, Dhruba; Tsutsumi, Atsushi

2014-08-01

Solid oxide fuel cells (SOFCs) are promising electrochemical energy conversion devices owing to their high power generation efficiency and environmentally benign operation. Micro-tubular SOFCs, which have diameters ranging from a few millimeters to the sub-millimeter scale, offer several advantages over competing SOFCs such as high volumetric power density, good endurance against thermal cycling, and flexible sealing between fuel and oxidant streams. Herein, we successfully realized a novel micro-tubular SOFC design based on a porous yttria-stabilized zirconia (YSZ) support using multi-step dip coating and co-sintering methods. The micro-tubular SOFC consisted of Ni-YSZ, YSZ, and strontium-doped lanthanum manganite (LSM)-YSZ as the anode, electrolyte, and cathode, respectively. In addition, to facilitate current collection from the anode and cathode, Ni and LSM were applied as an anode current collector and cathode current collector, respectively. Micro-crystalline cellulose was selected as a pore former to achieve better shrinkage behavior of the YSZ support so that the electrolyte layer could be densified at a co-sintering temperature of 1300°C. The developed micro-tubular design showed a promising electrochemical performance with maximum power densities of 525, 442, and 354 mW cm-2 at 850, 800, and 750°C, respectively.

Risk-aware multi-armed bandit problem with application to portfolio selection

PubMed Central

Huo, Xiaoguang

2017-01-01

Sequential portfolio selection has attracted increasing interest in the machine learning and quantitative finance communities in recent years. As a mathematical framework for reinforcement learning policies, the stochastic multi-armed bandit problem addresses the primary difficulty in sequential decision-making under uncertainty, namely the exploration versus exploitation dilemma, and therefore provides a natural connection to portfolio selection. In this paper, we incorporate risk awareness into the classic multi-armed bandit setting and introduce an algorithm to construct portfolio. Through filtering assets based on the topological structure of the financial market and combining the optimal multi-armed bandit policy with the minimization of a coherent risk measure, we achieve a balance between risk and return. PMID:29291122

Risk-aware multi-armed bandit problem with application to portfolio selection.

PubMed

Huo, Xiaoguang; Fu, Feng

2017-11-01

Sequential portfolio selection has attracted increasing interest in the machine learning and quantitative finance communities in recent years. As a mathematical framework for reinforcement learning policies, the stochastic multi-armed bandit problem addresses the primary difficulty in sequential decision-making under uncertainty, namely the exploration versus exploitation dilemma, and therefore provides a natural connection to portfolio selection. In this paper, we incorporate risk awareness into the classic multi-armed bandit setting and introduce an algorithm to construct portfolio. Through filtering assets based on the topological structure of the financial market and combining the optimal multi-armed bandit policy with the minimization of a coherent risk measure, we achieve a balance between risk and return.

Negative effects of microplastic exposure on growth and development of Crepidula onyx.

PubMed

Lo, Hau Kwan Abby; Chan, Kit Yu Karen

2018-02-01

Microplastics exposure could be detrimental to marine organisms especially under high concentrations. However, few studies have considered the multiphasic nature of marine invertebrates' life history and investigated the impact of experiencing microplastics during early development on post-metamorphic stages (legacy effect). Many planktonic larvae can feed selectively and it is unclear whether such selectivity could modulate the impact of algal food-sized microplastic. In this two-stage experiment, veligers of Crepidula onyx were first exposed to additions of algae-sized micro-polystyrene (micro-PS) beads at different concentrations, including ones that were comparable their algal diet. These additions were then either halted or continued after settlement. At environmentally relevant concentration (ten 2-μm microplastic beads ml -1 ), larval and juvenile C. onyx was not affected. At higher concentrations, these micro-PS fed larvae consumed a similar amount of algae compared to those in control but grew relatively slower than those in the control suggesting that ingestion and/or removal of microplastic was/were energetically costly. These larvae also settled earlier at a smaller size compared to the control, which could negatively affect post-settlement success. Juvenile C. onyx receiving continuous micro-PS addition had slower growth rates. Individuals only exposed to micro-PS during their larval stage continued to have slower growth rates than those in the control even if micro-PS had been absent in their surroundings for 65 days highlighting a legacy effect of microplastic exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-efficiency single cell encapsulation and size selective capture of cells in picoliter droplets based on hydrodynamic micro-vortices.

PubMed

Kamalakshakurup, Gopakumar; Lee, Abraham P

2017-12-05

Single cell analysis has emerged as a paradigm shift in cell biology to understand the heterogeneity of individual cells in a clone for pathological interrogation. Microfluidic droplet technology is a compelling platform to perform single cell analysis by encapsulating single cells inside picoliter-nanoliter (pL-nL) volume droplets. However, one of the primary challenges for droplet based single cell assays is single cell encapsulation in droplets, currently achieved either randomly, dictated by Poisson statistics, or by hydrodynamic techniques. In this paper, we present an interfacial hydrodynamic technique which initially traps the cells in micro-vortices, and later releases them one-to-one into the droplets, controlled by the width of the outer streamline that separates the vortex from the flow through the streaming passage adjacent to the aqueous-oil interface (d gap ). One-to-one encapsulation is achieved at a d gap equal to the radius of the cell, whereas complete trapping of the cells is realized at a d gap smaller than the radius of the cell. The unique feature of this technique is that it can perform 1. high efficiency single cell encapsulations and 2. size-selective capturing of cells, at low cell loading densities. Here we demonstrate these two capabilities with a 50% single cell encapsulation efficiency and size selective separation of platelets, RBCs and WBCs from a 10× diluted blood sample (WBC capture efficiency at 70%). The results suggest a passive, hydrodynamic micro-vortex based technique capable of performing high-efficiency single cell encapsulation for cell based assays.

Decoupled macro/micro-manipulator for fast and precise assembly operations: design and experiments

NASA Astrophysics Data System (ADS)

Hodac, Agathe; Siegwart, Roland Y.

1999-08-01

This paper presents a high performance single arm robot configuration, based on a macro-manipulator coupled with a micro-manipulator. The system is well suited to fast and precise positioning tasks for repetitive pick and place applications in the manufacturing industry. Firstly, the paper focuses on the design of the micro-manipulator, particularly on the selection of the proper micro-actuator type and location. We show that the micro-manipulator's design with an actuator placed between endpoint and ground and with a flexible suspension system can reduce the dynamic coupling between the macro-manipulator and the micro- manipulator. The overall system performance can then be improved. We describe two different designs of compact and fast micro-manipulators composed of voice coil actuators and a monolithic flexure suspension with notch hinges. Secondly, the paper presents a control strategy that allows both correction of possible misalignments of the end-effector relative to the target and compensation of tip oscillations. The dynamic interaction is analyzed and stability is verified. Finally, experimental results demonstrate significant improvements in acceleration, endpoint accuracy and settling time achieved by the novel configuration of the macro/micro-manipulator.

On the Sequential Negotiation of Identity in Spanish-Language Discourse: Mobilizing Linguistic Resources in the Service of Social Action

ERIC Educational Resources Information Center

Raymond, Chase Wesley

2014-01-01

This dissertation takes an ethnomethodologically-grounded, conversation-analytic approach in investigating the sequential deployment of linguistic resources in Spanish-language talk-in-interaction. Three sets of resources are examined: 2nd-person singular reference forms (tú, vos, usted), indicative/subjunctive verbal mood selection, and…

Evaluating Bias of Sequential Mixed-Mode Designs against Benchmark Surveys

ERIC Educational Resources Information Center

Klausch, Thomas; Schouten, Barry; Hox, Joop J.

2017-01-01

This study evaluated three types of bias--total, measurement, and selection bias (SB)--in three sequential mixed-mode designs of the Dutch Crime Victimization Survey: telephone, mail, and web, where nonrespondents were followed up face-to-face (F2F). In the absence of true scores, all biases were estimated as mode effects against two different…

High-Throughput Sequencing Reveals Diverse Sets of Conserved, Nonconserved, and Species-Specific miRNAs in Jute

PubMed Central

Islam, Md. Tariqul; Ferdous, Ahlan Sabah; Najnin, Rifat Ara; Sarker, Suprovath Kumar; Khan, Haseena

2015-01-01

MicroRNAs play a pivotal role in regulating a broad range of biological processes, acting by cleaving mRNAs or by translational repression. A group of plant microRNAs are evolutionarily conserved; however, others are expressed in a species-specific manner. Jute is an agroeconomically important fibre crop; nonetheless, no practical information is available for microRNAs in jute to date. In this study, Illumina sequencing revealed a total of 227 known microRNAs and 17 potential novel microRNA candidates in jute, of which 164 belong to 23 conserved families and the remaining 63 belong to 58 nonconserved families. Among a total of 81 identified microRNA families, 116 potential target genes were predicted for 39 families and 11 targets were predicted for 4 among the 17 identified novel microRNAs. For understanding better the functions of microRNAs, target genes were analyzed by Gene Ontology and their pathways illustrated by KEGG pathway analyses. The presence of microRNAs identified in jute was validated by stem-loop RT-PCR followed by end point PCR and qPCR for randomly selected 20 known and novel microRNAs. This study exhaustively identifies microRNAs and their target genes in jute which will ultimately pave the way for understanding their role in this crop and other crops. PMID:25861616

Mercury(II) and methyl mercury determinations in water and fish samples by using solid phase extraction and cold vapour atomic absorption spectrometry combination.

PubMed

Tuzen, Mustafa; Karaman, Isa; Citak, Demirhan; Soylak, Mustafa

2009-07-01

A method has been developed for mercury(II) and methyl mercury speciation on Staphylococcus aureus loaded Dowex Optipore V-493 micro-column in the presented work, by using cold vapour atomic absorption spectrometry. Selective and sequential elution with 0.1 molL(-1) HCl for methyl mercury and 2 molL(-1) HCl for mercury(II) were performed at the pH range of 2-6. Optimal analytical conditions including pH, amounts of biosorbent, sample volumes were investigated. The detection limits of the analytes were 2.5 ngL(-1) for Hg(II) and 1.7 ngL(-1) for methyl mercury. The capacity of biosorbent for mercury(II) and methyl mercury was 6.5 and 5.4 mgg(-1), respectively. The validation of the presented procedure is performed by the analysis of standard reference material. The speciation procedure established was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and microwave digested fish samples.

Sequential solvent extraction for forms of antimony in five selected coals

USGS Publications Warehouse

Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

2008-01-01

Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 ??g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate- plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matterbound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism. ?? 2008 by The University of Chicago. All rights reserved.

[Professor GAO Yuchun's experience on "sequential acupuncture leads to smooth movement of qi"].

PubMed

Wang, Yanjun; Xing, Xiao; Cui, Linhua

2016-01-01

Professor GAO Yuchun is considered as the key successor of GAO's academic school of acupuncture and moxibustion in Yanzhao region. Professor GAO's clinical experience of, "sequential acupuncture" is introduced in details in this article. In Professor GAO's opinions, appropriate acupuncture sequence is the key to satisfactory clinical effects during treatment. Based on different acupoints, sequential acupuncture can achieve the aim of qi following needles and needles leading qi; based on different symptoms, sequential acupuncture can regulate qi movement; based on different body positions, sequential acupuncture can harmonize qi-blood and reinforcing deficiency and reducing excess. In all, according to the differences of disease condition and constitution, based on the accurate acupoint selection and appropriate manipulation, it is essential to capture the nature of diseases and make the order of acupuncture, which can achieve the aim of regulating qi movement and reinforcing deficiency and reducing excess.

Analytical performance of a versatile laboratory microscopic X-ray fluorescence system for metal uptake studies on argillaceous rocks

NASA Astrophysics Data System (ADS)

Gergely, Felicián; Osán, János; Szabó, B. Katalin; Török, Szabina

2016-02-01

Laboratory-scale microscopic X-ray fluorescence (micro-XRF) plays an increasingly important role in various fields where multielemental investigations of samples are indispensable. In case of geological samples, the reasonable detection limits (LOD) and spatial resolutions are necessary to identify the trace element content in microcrystalline level. The present study focuses on the analytical performance of a versatile laboratory-scale micro-XRF system with various options of X-ray sources and detectors to find the optimal experimental configuration in terms of sensitivities and LOD for selected elements in loaded petrographic thin sections. The method was tested for sorption studies involving thin sections prepared from cores of Boda Claystone Formation, which is a potential site for a high-level radioactive waste repository. Loaded ions in the sorption measurements were Cs(I) and Ni(II) chemically representing fission and corrosion products. Based on the collected elemental maps, the correlation between the elements representative of main rock components and the selected loaded ion was studied. For the elements of interest, Cs(I) and Ni(II) low-power iMOXS source with polycapillary and silicon drift detector was found to be the best configuration to reach the optimal LOD values. Laboratory micro-XRF was excellent to identify the responsible key minerals for the uptake of Cs(I). In case of nickel, careful corrections were needed because of the relatively high Ca content of the rock samples. The results were compared to synchrotron radiation micro-XRF.

Sequence-based design of bioactive small molecules that target precursor microRNAs.

PubMed

Velagapudi, Sai Pradeep; Gallo, Steven M; Disney, Matthew D

2014-04-01

Oligonucleotides are designed to target RNA using base pairing rules, but they can be hampered by poor cellular delivery and nonspecific stimulation of the immune system. Small molecules are preferred as lead drugs or probes but cannot be designed from sequence. Herein, we describe an approach termed Inforna that designs lead small molecules for RNA from solely sequence. Inforna was applied to all human microRNA hairpin precursors, and it identified bioactive small molecules that inhibit biogenesis by binding nuclease-processing sites (44% hit rate). Among 27 lead interactions, the most avid interaction is between a benzimidazole (1) and precursor microRNA-96. Compound 1 selectively inhibits biogenesis of microRNA-96, upregulating a protein target (FOXO1) and inducing apoptosis in cancer cells. Apoptosis is ablated when FOXO1 mRNA expression is knocked down by an siRNA, validating compound selectivity. Markedly, microRNA profiling shows that 1 only affects microRNA-96 biogenesis and is at least as selective as an oligonucleotide.

Sequence-based design of bioactive small molecules that target precursor microRNAs

PubMed Central

Velagapudi, Sai Pradeep; Gallo, Steven M.; Disney, Matthew D.

2014-01-01

Oligonucleotides are designed to target RNA using base pairing rules, however, they are hampered by poor cellular delivery and non-specific stimulation of the immune system. Small molecules are preferred as lead drugs or probes, but cannot be designed from sequence. Herein, we describe an approach termed Inforna that designs lead small molecules for RNA from solely sequence. Inforna was applied to all human microRNA precursors and identified bioactive small molecules that inhibit biogenesis by binding to nuclease processing sites (41% hit rate). Amongst 29 lead interactions, the most avid interaction is between a benzimidazole (1) and precursor microRNA-96. Compound 1 selectively inhibits biogenesis of microRNA-96, upregulating a protein target (FOXO1) and inducing apoptosis in cancer cells. Apoptosis is ablated when FOXO1 mRNA expression is knocked down by an siRNA, validating compound selectivity. Importantly, microRNA profiling shows that 1 only significantly effects microRNA-96 biogenesis and is more selective than an oligonucleotide. PMID:24509821

Prototype color field sequential television lens assembly

NASA Technical Reports Server (NTRS)

1974-01-01

The design, development, and evaluation of a prototype modular lens assembly with a self-contained field sequential color wheel is presented. The design of a color wheel of maximum efficiency, the selection of spectral filters, and the design of a quiet, efficient wheel drive system are included. Design tradeoffs considered for each aspect of the modular assembly are discussed. Emphasis is placed on achieving a design which can be attached directly to an unmodified camera, thus permitting use of the assembly in evaluating various candidate camera and sensor designs. A technique is described which permits maintaining high optical efficiency with an unmodified camera. A motor synchronization system is developed which requires only the vertical synchronization signal as a reference frequency input. Equations and tradeoff curves are developed to permit optimizing the filter wheel aperture shapes for a variety of different design conditions.

Micro/nano-particle decorated metal wire for cutting soft matter

NASA Astrophysics Data System (ADS)

Zhang, Wei; Feng, Liang-liang; Wu, Fan; Zhang, Run-run; Wu, Cheng-wei

2016-09-01

To cut soft materials such as biological tissues with minimal damage and reduced positional error is highly desired in medical surgery and biomechanics. After years of natural selection and evolution, mosquitoes have acquired the ability to insert their proboscises into human skin with astonishingly tiny forces. This can be associated with the unique structure of their proboscises, with micro/nano sawteeth, and the distinctive insertion manner: high frequency reciprocating saw cutting. Inspired by these, this communication describes the successful implantation of metal oxide particles onto molybdenum wire surfaces through a sol-calcination process, to form a biomimetic sawblade with a high density of micro/nano saw teeth, where the acidification is essential in terms of generating active anchoring sites on the wire. When used as a sawblade in conjunction with reciprocating action to cut the viscoelastic gel, both the cut-in force and cut-in displacement could be decreased substantially. The cutting speed and frequency of reciprocating action are important operating parameters influencing cut-in force.

Promising applications of graphene and graphene-based nanostructures

NASA Astrophysics Data System (ADS)

Nguyen, Bich Ha; Hieu Nguyen, Van

2016-06-01

The present article is a review of research works on promising applications of graphene and graphene-based nanostructures. It contains five main scientific subjects. The first one is the research on graphene-based transparent and flexible conductive films for displays and electrodes: efficient method ensuring uniform and controllable deposition of reduced graphene oxide thin films over large areas, large-scale pattern growth of graphene films for stretchble transparent electrodes, utilization of graphene-based transparent conducting films and graphene oxide-based ones in many photonic and optoelectronic devices and equipments such as the window electrodes of inorganic, organic and dye-sensitized solar cells, organic light-emitting diodes, light-emitting electrochemical cells, touch screens, flexible smart windows, graphene-based saturated absorbers in laser cavities for ultrafast generations, graphene-based flexible, transparent heaters in automobile defogging/deicing systems, heatable smart windows, graphene electrodes for high-performance organic field-effect transistors, flexible and transparent acoustic actuators and nanogenerators etc. The second scientific subject is the research on conductive inks for printed electronics to revolutionize the electronic industry by producing cost-effective electronic circuits and sensors in very large quantities: preparing high mobility printable semiconductors, low sintering temperature conducting inks, graphene-based ink by liquid phase exfoliation of graphite in organic solutions, and developing inkjet printing technique for mass production of high-quality graphene patterns with high resolution and for fabricating a variety of good-performance electronic devices, including transparent conductors, embedded resistors, thin-film transistors and micro supercapacitors. The third scientific subject is the research on graphene-based separation membranes: molecular dynamics simulation study on the mechanisms of the transport of molecules, vapors and gases through nanopores in graphene membranes, experimental works investigating selective transport of different molecules through nanopores in single-layer graphene and graphene-based membranes toward the water desalination, chemical mixture separation and gas control. Various applications of graphene in bio-medicine are the contents of the fourth scientific subject of the review. They include the DNA translocations through nanopores in graphene membranes toward the fabrication of devices for genomic screening, in particular DNA sequencing; subnanometre trans-electrode membranes with potential applications to the fabrication of very high resolution, high throughput nanopore-based single-molecule detectors; antibacterial activity of graphene, graphite oxide, graphene oxide and reduced graphene oxide; nanopore sensors for nucleic acid analysis; utilization of graphene multilayers as the gates for sequential release of proteins from surface; utilization of graphene-based electroresponsive scaffolds as implants for on-demand drug delivery etc. The fifth scientific subject of the review is the research on the utilization of graphene in energy storage devices: ternary self-assembly of ordered metal oxide-graphene nanocomposites for electrochemical energy storage; self-assembled graphene/carbon nanotube hybrid films for supercapacitors; carbon-based supercapacitors fabricated by activation of graphene; functionalized graphene sheet-sulfure nanocomposite for using as cathode material in rechargeable lithium batteries; tunable three-dimensional pillared carbon nanotube-graphene networks for high-performance capacitance; fabrications of electrochemical micro-capacitors using thin films of carbon nanotubes and chemically reduced graphenes; laser scribing of high-performance and flexible graphene-based electrochemical capacitors; emergence of next-generation safe batteries featuring graphene-supported Li metal anode with exceptionally high energy or power densities; fabrication of anodes for lithium ion batteries from crumpled graphene-encapsulated Si nanoparticles; liquid-mediated dense integration of graphene materials for compact capacitive energy storage; scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage; superior micro-supercapacitors based on graphene quantum dots; all-graphene core-sheat microfibres for all-solid-state, stretchable fibriform supercapacitors and wearable electronic textiles; micro-supercapacitors with high electrochemical performance based on three-dimensional graphene-carbon nanotube carpets; macroscopic nitrogen-doped graphene hydrogels for ultrafast capacitors; manufacture of scalable ultra-thin and high power density graphene electrochemical capacitor electrodes by aqueous exfoliation and spray deposition; scalable synthesis of hierarchically structured carbon nanotube-graphene fibers for capacitive energy storage; phosphorene-graphene hybrid material as a high-capacity anode material for sodium-ion batteries. Beside above-presented promising applications of graphene and graphene-based nanostructures, other less widespread, but perhaps not less important, applications of graphene and graphene-based nanomaterials, are also briefly discussed.

Straightforward Entry toward Highly Substituted 2,3-Dihydrobenz[ b]oxepines by Ring Expansion of Benzopyryliums with Donor-Acceptor Diazo Compounds.

PubMed

Courant, Thibaut; Pasco, Morgane; Lecourt, Thomas

2018-05-04

Ylide-type reactivity of diazo compounds is exploited in a new way to prepare benzo[ b]oxepines thanks to the formation of three chemical bonds and two contiguous and highly substituted stereocenters in a single pot. This cationic reaction cascade first involves addition of a donor-acceptor-substituted diazo compound to a benzopyrylium. Selective 1,2 migration of the endocyclic C-C bond then results in a ring-expansion and generates a second oxocarbenium that is trapped by a nucleophile added sequentially.

Effect of thiorphan on response of the guinea-pig gallbladder to tachykinins.

PubMed

Maggi, C A; Patacchini, R; Renzi, D; Santicioli, P; Regoli, D; Rovero, P; Drapeau, G; Surrenti, C; Meli, A

1989-06-08

Tachykinins produced a concentration-related contraction of the isolated guinea-pig gallbladder, with a rank order of potency neurokinin A (NKA) greater than Arg-neurokinin B = neurokinin B (NKB) greater than substance P (SP). Only the effect of SP was potentiated by thiorphan (0.1-10 microM). A significant enhancement of the response to SP was also produced by captopril (1 microM). [Nle10]NKA-(4-10) and [beta-Ala8]NKA-(4-10), selective NK-2 receptor agonists, were active, whereas [Pro9]SP sulfone (selective NK-1 agonist) was almost ineffective. [MePhe7]NKB (selective NK-3 agonist) had some activity but only at high concentrations. Septide was almost ineffective and DiMeC7 had an action comparable to that of [MePhe7]NKB. None of the effects induced by these synthetic tachykinin analogs were significantly potentiated by thiorphan. Capsaicin (10 microM) produced a contraction which was unaffected by thiorphan. Both capsaicin and NKA-induced contractions were antagonized by Spantide at concentrations (5-10 microM) which had no effect against the atropine-sensitive contractions produced by electrical field stimulation. Capsaicin (1 microM) produced a consistent release of SP-like immunoreactivity (SP-LI) and a second application of the drug had no further effect, indicating complete desensitization. SP-LI release by capsaicin was almost doubled in the presence of thiorphan. These findings indicate that NK-2 and possibly some NK-3 receptors mediate the contractile response of the guinea-pig gallbladder to tachykinins. Both exogenous and endogenous (released by capsaicin) SP were degraded to a significant extent in this organ via a thiorphan-sensitive mechanism, the identity of which remains to be established.

MicroCT angiography detects vascular formation and regression in skin wound healing.

PubMed

Urao, Norifumi; Okonkwo, Uzoagu A; Fang, Milie M; Zhuang, Zhen W; Koh, Timothy J; DiPietro, Luisa A

2016-07-01

Properly regulated angiogenesis and arteriogenesis are essential for effective wound healing. Tissue injury induces robust new vessel formation and subsequent vessel maturation, which involves vessel regression and remodeling. Although formation of functional vasculature is essential for healing, alterations in vascular structure over the time course of skin wound healing are not well understood. Here, using high-resolution ex vivo X-ray micro-computed tomography (microCT), we describe the vascular network during healing of skin excisional wounds with highly detailed three-dimensional (3D) reconstructed images and associated quantitative analysis. We found that relative vessel volume, surface area and branching number are significantly decreased in wounds from day 7 to days 14 and 21. Segmentation and skeletonization analysis of selected branches from high-resolution images as small as 2.5μm voxel size show that branching orders are decreased in the wound vessels during healing. In histological analysis, we found that the contrast agent fills mainly arterioles, but not small capillaries nor large veins. In summary, high-resolution microCT revealed dynamic alterations of vessel structures during wound healing. This technique may be useful as a key tool in the study of the formation and regression of wound vessels. Copyright © 2016 Elsevier Inc. All rights reserved.

Design, fabrication and testing of hierarchical micro-optical structures and systems

NASA Astrophysics Data System (ADS)

Cannistra, Aaron Thomas

Micro-optical systems are becoming essential components in imaging, sensing, communications, computing, and other applications. Optically based designs are replacing electronic, chemical and mechanical systems for a variety of reasons, including low power consumption, reduced maintenance, and faster operation. However, as the number and variety of applications increases, micro-optical system designs are becoming smaller, more integrated, and more complicated. Micro and nano-optical systems found in nature, such as the imaging systems found in many insects and crustaceans, can have highly integrated optical structures that vary in size by orders of magnitude. These systems incorporate components such as compound lenses, anti-reflective lens surface structuring, spectral filters, and polarization selective elements. For animals, these hybrid optical systems capable of many optical functions in a compact package have been repeatedly selected during the evolutionary process. Understanding the advantages of these designs gives motivation for synthetic optical systems with comparable functionality. However, alternative fabrication methods that deviate from conventional processes are needed to create such systems. Further complicating the issue, the resulting device geometry may not be readily compatible with existing measurement techniques. This dissertation explores several nontraditional fabrication techniques for optical components with hierarchical geometries and measurement techniques to evaluate performance of such components. A micro-transfer molding process is found to produce high-fidelity micro-optical structures and is used to fabricate a spectral filter on a curved surface. By using a custom measurement setup we demonstrate that the spectral filter retains functionality despite the nontraditional geometry. A compound lens is fabricated using similar fabrication techniques and the imaging performance is analyzed. A spray coating technique for photoresist application to curved surfaces combined with interference lithography is also investigated. Using this technique, we generate polarizers on curved surfaces and measure their performance. This work furthers an understanding of how combining multiple optical components affects the performance of each component, the final integrated devices, and leads towards realization of biomimetically inspired imaging systems.

Rate-dependent inverse-addition beta-selective mannosylation and contiguous sequential glycosylation involving beta-mannosidic bond formation.

PubMed

Chang, Shih-Sheng; Shih, Che-Hao; Lai, Kwun-Cheng; Mong, Kwok-Kong Tony

2010-05-03

The beta-selectivity of mannosylation has been found to be dependent on the addition rate of the mannosyl trichloroacetimidate donor in an inverse-addition (I-A) procedure. This rate dependent I-A procedure can improve the selectivity of direct beta-mannosylation and is applicable to orthogonal glycosylations of thioglycoside acceptors. Further elaboration of this novel procedure enables the development of the contiguous sequential glycosylation strategy, which streamlines the preparation of oligosaccharides invoking beta-mannosidic bond formation. The synthetic utility of the contiguous glycosylation strategy was demonstrated by the preparation of the trisaccharide core of human N-linked glycoproteins and the trisaccharide repeating unit of the O-specific polysaccharide found in the cellular capsule of Salmonelle bacteria.

Exposure to 50 Hz magnetic field in apartment buildings with built-in transformer stations in Hungary.

PubMed

Thuróczy, György; Jánossy, Gábor; Nagy, Noémi; Bakos, József; Szabó, Judit; Mezei, Gábor

2008-01-01

Exposure to 50 Hz magnetic field (MF) was evaluated in 31 multi-level apartment buildings with built-in step-down transformer stations. In each building, three apartments were selected: one apartment located immediately above the transformer room (index apartment), one located on the same floor and one on a higher floor. The mean value of measured MFs was 0.98 microT in apartments above transformers, 0.13 microT on the same floor, and 0.1 microT in on higher floors. The mean measured MF value was higher than 0.2 microT in 30 (97%) index apartments, 4 (14%) on the same floor as the index apartments and 4 (13%) on higher floors. The corresponding numbers were 25 (81%), 0 and 0, respectively, when 0.4 microT was used as cut-point. It is concluded that apartments in building with built-in transformers can be reliably classified into high and low-exposure categories based on their location in relation to transformers.

Building emotional resilience over 14 sessions of emotion focused therapy: Micro-longitudinal analyses of productive emotional patterns.

PubMed

Pascual-Leone, A; Yeryomenko, N; Sawashima, T; Warwar, S

2017-05-04

Pascual-Leone and Greenberg's sequential model of emotional processing has been used to explore process in over 24 studies. This line of research shows emotional processing in good psychotherapy often follows a sequential order, supporting a saw-toothed pattern of change within individual sessions (progressing "2-steps-forward, 1-step-back"). However, one cannot assume that local in-session patterns are scalable across an entire course of therapy. Thus, the primary objective of this exploratory study was to consider how the sequential patterns identified by Pascual-Leone, may apply across entire courses of treatment. Intensive emotion coding in two separate single-case designs were submitted for quantitative analyses of longitudinal patterns. Comprehensive coding in these cases involved recording observations for every emotional event in an entire course of treatment (using the Classification of Affective-Meaning States), which were then treated as a 9-point ordinal scale. Applying multilevel modeling to each of the two cases showed significant patterns of change over a large number of sessions, and those patterns were either nested at the within-session level or observed at the broader session-by-session level of change. Examining successful treatment cases showed several theoretically coherent kinds of temporal patterns, although not always in the same case. Clinical or methodological significance of this article: This is the first paper to demonstrate systematic temporal patterns of emotion over the course of an entire treatment. (1) The study offers a proof of concept that longitudinal patterns in the micro-processes of emotion can be objectively derived and quantified. (2) It also shows that patterns in emotion may be identified on the within-session level, as well as the session-by-session level of analysis. (3) Finally, observed processes over time support the ordered pattern of emotional states hypothesized in Pascual-Leone and Greenberg's ( 2007 ) model of emotional processing.

Reproductive practices by patterns of marriage among Iranian women: study protocol for an explanatory sequential mixed methods design.

PubMed

Taghizadeh, Ziba; Vedadhir, Abouali; Behmanesh, Fereshteh; Ebadi, Abbas; Pourreza, Abulghasem; Abbasi-Shavazi, Mohammad Jalal

2015-09-18

Nowadays, nearly half of the world population lives in societies with low fertility or the below-replacement fertility. This potentially grounds the critical situation of reduction in the workforce and causes the aging of population due to an overall increase in life expectancy and standard of living. Hence, population and its transitions including the issue of fertility decline has become a topic of intense debate in the agenda-setting and policy-making processes in both the developed and developing countries. In this view, what can practically be done to respond to the fertility decline that entails effectively addressing the determinants of fertility change? In line with the literature, how people form their marriages or patterns of marriage is amongst influencing factors which potentially affect their reproductive practices as diverse societies recognize different conventions for marriage. This study is to examine women's reproductive practices by the various patterns of marriage using the explanatory sequential mixed methods design. This study has an explanatory sequential mixed methods design, the follow-up explanations variant model, with two strands. This design will be implemented in two distinct phases. In the first phase, a cross-sectional quantitative study will be done using a cluster sampling strategy on 850 married women 15-49 years old living in Babol city, Iran. In order to obtain a deeper understanding of the results of the quantitative phase, researchers will implement a qualitative research in the second phase of this study. This design will provide an explanation of the quantitative research results using the qualitative evidence. As patterns of marriage have implications for the status of women, their health and fertility, the result of this study can provide a rich source of information for the required health-related interventions and policies are required to put the demographic changes on the right track at micro and macro level and improve the reproductive practices of women at micro level.

The optional selection of micro-motion feature based on Support Vector Machine

NASA Astrophysics Data System (ADS)

Li, Bo; Ren, Hongmei; Xiao, Zhi-he; Sheng, Jing

2017-11-01

Micro-motion form of target is multiple, different micro-motion forms are apt to be modulated, which makes it difficult for feature extraction and recognition. Aiming at feature extraction of cone-shaped objects with different micro-motion forms, this paper proposes the best selection method of micro-motion feature based on support vector machine. After the time-frequency distribution of radar echoes, comparing the time-frequency spectrum of objects with different micro-motion forms, features are extracted based on the differences between the instantaneous frequency variations of different micro-motions. According to the methods based on SVM (Support Vector Machine) features are extracted, then the best features are acquired. Finally, the result shows the method proposed in this paper is feasible under the test condition of certain signal-to-noise ratio(SNR).

Macro and micro geo-spatial environment consideration for landfill site selection in Sharjah, United Arab Emirates.

PubMed

Al-Ruzouq, Rami; Shanableh, Abdallah; Omar, Maher; Al-Khayyat, Ghadeer

2018-02-17

Waste management involves various procedures and resources for proper handling of waste materials in compliance with health codes and environmental regulations. Landfills are one of the oldest, most convenient, and cheapest methods to deposit waste. However, landfill utilization involves social, environmental, geotechnical, cost, and restrictive regulation considerations. For instance, landfills are considered a source of hazardous air pollutants that can cause health and environmental problems related to landfill gas and non-methanic organic compounds. The increasing number of sensors and availability of remotely sensed images along with rapid development of spatial technology are helping with effective landfill site selection. The present study used fuzzy membership and the analytical hierarchy process (AHP) in a geo-spatial environment for landfill site selection in the city of Sharjah, United Arab Emirates. Macro- and micro-level factors were considered; the macro-level contained social and economic factors, while the micro-level accounted for geo-environmental factors. The weighted spatial layers were combined to generate landfill suitability and overall suitability index maps. Sensitivity analysis was then carried out to rectify initial theoretical weights. The results showed that 30.25% of the study area had a high suitability index for landfill sites in the Sharjah, and the most suitable site was selected based on weighted factors. The developed fuzzy-AHP methodology can be applied in neighboring regions with similar geo-natural conditions.

Value for money in changing clinical practice: should decisions about guidelines and implementation strategies be made sequentially or simultaneously?

PubMed

Hoomans, Ties; Severens, Johan L; Evers, Silvia M A A; Ament, Andre J H A

2009-01-01

Decisions about clinical practice change, that is, which guidelines to adopt and how to implement them, can be made sequentially or simultaneously. Decision makers adopting a sequential approach first compare the costs and effects of alternative guidelines to select the best set of guideline recommendations for patient management and subsequently examine the implementation costs and effects to choose the best strategy to implement the selected guideline. In an integral approach, decision makers simultaneously decide about the guideline and the implementation strategy on the basis of the overall value for money in changing clinical practice. This article demonstrates that the decision to use a sequential v. an integral approach affects the need for detailed information and the complexity of the decision analytic process. More importantly, it may lead to different choices of guidelines and implementation strategies for clinical practice change. The differences in decision making and decision analysis between the alternative approaches are comprehensively illustrated using 2 hypothetical examples. We argue that, in most cases, an integral approach to deciding about change in clinical practice is preferred, as this provides more efficient use of scarce health-care resources.

Islet organogenesis, angiogenesis and innervation.

PubMed

Cerf, Marlon E

2011-11-01

The pancreas is characterized by a major component, an exocrine and ductal system involved in digestion, and a minor component, the endocrine islets represented by islet micro-organs that tightly regulate glucose homoeostasis. Pancreatic organogenesis is strictly co-ordinated by transcription factors that are expressed sequentially to yield functional islets capable of maintaining glucose homoeostasis. Angiogenesis and innervation complete islet development, equipping islets to respond to metabolic demands. Proper regulation of this triad of processes during development is critical for establishing functional islets.

Synergistic anticancer effects of combined gamma-tocotrienol and celecoxib treatment are associated with suppression in Akt and NFkappaB signaling.

PubMed

Shirode, Amit B; Sylvester, Paul W

2010-05-01

The selective cyclooxygenase (COX)-2 inhibitor, celecoxib, and the vitamin E isoform, gamma-tocotrienol, both display potent anticancer activity. However, high dose clinical use of selective COX-2 inhibitors has been limited by gastrointestinal and cardiovascular toxicity, whereas limited absorption and transport of gamma-tocotrienol by the body has made it difficult to obtain and sustain therapeutic levels in the blood and target tissues. Studies were conducted to characterize the synergistic anticancer antiproliferative effects of combined low dose celecoxib and gamma-tocotrienol treatment on mammary tumor cells in culture. The highly malignant mouse +SA mammary epithelial cells were maintained in culture on serum-free defined control or treatment media. Treatment effects on COX-1, COX-2, Akt, NFkappaB and prostaglandin E(2) (PGE(2)) synthesis were assessed following a 3- or 4-day culture period. Treatment with 3-4 microM gamma-tocotrienol or 7.5-10 microM celecoxib alone significantly inhibited +SA cell growth in a dose-responsive manner. However, combined treatment with subeffective doses of gamma-tocotrienol (0.25 microM) and celecoxib (2.5 microM) resulted in a synergistic antiproliferative effect, as determined by isobologram analysis, and this growth inhibitory effect was associated with a reduction in PGE(2) synthesis, and decrease in COX-2, phospho-Akt (active), and phospho-NFkappaB (active) levels. These results demonstrate that the synergistic anticancer effects of combined celecoxib and gamma-tocotrienol therapy are mediated by COX-2 dependent and independent mechanisms. These findings also suggest that combination therapy with these agents may provide enhanced therapeutic response in breast cancer patients, while avoiding the toxicity associated with high-dose COX-2 inhibitor monotherapy. 2009 Elsevier Masson SAS. All rights reserved.

Palladium-tin catalysts for the direct synthesis of H 2O 2 with high selectivity

DOE PAGES

Freakley, Simon J.; He, Qian; Harrhy, Jonathan H.; ...

2016-02-25

The direct synthesis of hydrogen peroxide (H 2O 2 ) from H 2 and O 2 represents a potentially atom-efficient alternative to the current industrial indirect process. We show that the addition of tin to palladium catalysts coupled with an appropriate heat treatment cycle switches off the sequential hydrogenation and decomposition reactions, enabling selectivities of >95% toward H 2O 2 . This effect arises from a tin oxide surface layer that encapsulates small Pd-rich particles while leaving larger Pd-Sn alloy particles exposed. In conclusion, we show that this effect is a general feature for oxide-supported Pd catalysts containing an appropriatemore » second metal oxide component, and we set out the design principles for producing high-selectivity Pd-based catalysts for direct H 2O 2 production that do not contain gold.« less

Classification of epileptic EEG signals based on simple random sampling and sequential feature selection.

PubMed

Ghayab, Hadi Ratham Al; Li, Yan; Abdulla, Shahab; Diykh, Mohammed; Wan, Xiangkui

2016-06-01

Electroencephalogram (EEG) signals are used broadly in the medical fields. The main applications of EEG signals are the diagnosis and treatment of diseases such as epilepsy, Alzheimer, sleep problems and so on. This paper presents a new method which extracts and selects features from multi-channel EEG signals. This research focuses on three main points. Firstly, simple random sampling (SRS) technique is used to extract features from the time domain of EEG signals. Secondly, the sequential feature selection (SFS) algorithm is applied to select the key features and to reduce the dimensionality of the data. Finally, the selected features are forwarded to a least square support vector machine (LS_SVM) classifier to classify the EEG signals. The LS_SVM classifier classified the features which are extracted and selected from the SRS and the SFS. The experimental results show that the method achieves 99.90, 99.80 and 100 % for classification accuracy, sensitivity and specificity, respectively.

Sequential two-photon double ionization of noble gases by circularly polarized XUV radiation

NASA Astrophysics Data System (ADS)

Gryzlova, E. V.; Grum-Grzhimailo, A. N.; Kuzmina, E. I.; Strakhova, S. I.

2014-10-01

Photoelectron angular distributions (PADs) and angular correlations between two emitted electrons in sequential two-photon double ionization (2PDI) of atoms by circularly polarized radiation are studied theoretically. In particular, the sequential 2PDI of the valence n{{p}6} shell in noble gas atoms (neon, argon, krypton) is analyzed, accounting for the first-order corrections to the dipole approximation. Due to different selection rules in ionization transitions, the circular polarization of photons causes some new features of the cross sections, PADs and angular correlation functions in comparison with the case of linearly polarized photons.

'Enzyme Test Bench': A biochemical application of the multi-rate modeling

NASA Astrophysics Data System (ADS)

Rachinskiy, K.; Schultze, H.; Boy, M.; Büchs, J.

2008-11-01

In the expanding field of 'white biotechnology' enzymes are frequently applied to catalyze the biochemical reaction from a resource material to a valuable product. Evolutionary designed to catalyze the metabolism in any life form, they selectively accelerate complex reactions under physiological conditions. Modern techniques, such as directed evolution, have been developed to satisfy the increasing demand on enzymes. Applying these techniques together with rational protein design, we aim at improving of enzymes' activity, selectivity and stability. To tap the full potential of these techniques, it is essential to combine them with adequate screening methods. Nowadays a great number of high throughput colorimetric and fluorescent enzyme assays are applied to measure the initial enzyme activity with high throughput. However, the prediction of enzyme long term stability within short experiments is still a challenge. A new high throughput technique for enzyme characterization with specific attention to the long term stability, called 'Enzyme Test Bench', is presented. The concept of the Enzyme Test Bench consists of short term enzyme tests conducted under partly extreme conditions to predict the enzyme long term stability under moderate conditions. The technique is based on the mathematical modeling of temperature dependent enzyme activation and deactivation. Adapting the temperature profiles in sequential experiments by optimum non-linear experimental design, the long term deactivation effects can be purposefully accelerated and detected within hours. During the experiment the enzyme activity is measured online to estimate the model parameters from the obtained data. Thus, the enzyme activity and long term stability can be calculated as a function of temperature. The results of the characterization, based on micro liter format experiments of hours, are in good agreement with the results of long term experiments in 1L format. Thus, the new technique allows for both: the enzyme screening with regard to the long term stability and the choice of the optimal process temperature. The presented article gives a successful example for the application of multi-rate modeling, experimental design and parameter estimation within biochemical engineering. At the same time, it shows the limitations of the methods at the state of the art and addresses the current problems to the applied mathematics community.

Vanguard: a Mars exobiology mission proposal using robotic elements

NASA Astrophysics Data System (ADS)

Ellery, A.; Richter, L.; Kolb, C.; Lammer, H.; Parnell, J.; Bertrand, R.; Ball, A.; Patel, M.; Coste, P.; McKee, G.

2003-04-01

We present a new proposal for a European exobiology-focussed robotic Mars mission. This mission is presented as a low-cost successor to the Mars Express/Beagle2 mission. The Mars surface segment is designed within the payload constraints of the current Mars Express bus spacecraft with a mass of 126 kg including the Entry, Descent and Landing System (EDLS). EDLS will be similar to that employed for Beagle2 and Mars Pathfinder. The surface segment will have a total mass of 66 kg including a 34 kg lander, a 26 kg micro-rover and three 1.6 kg moles. The exobiology focus requires that investigation of the Martian sub-surface, below the oxidised layer, be undertaken in search of biomolecular species. The currently favoured site for deployment is the Gusev palaeolake crater. The moles are mounted vertically to the rear of the micro-rover which will enable a surface traverse of 1-5 km. Each molewill be deployed sequentially at different sites selected during the mission operation. Each mole will penetrate below the projected depth of the oxidised layer (estimated at 2-3m depth) to a total depth of 5m. The micro-rover will carry the main scientific instrument pack of a combined confocal imager, Raman spectrometer, infrared spectrometer and laser plasma spectrometer. Each of these instruments enables remote sensing of mineralogy, elemental abundance, biomolecules and water signatures with depth. The implementation of a dedicated tether to each mole from the micro-rover provides the provision of power and optical fibre links from the instruments to the sub-surface targets. As remote sensing instruments, there is no requirement for the recovery of physical samples, eliminating much of the complexity inherent in recovering the moles. Each mole is thus deployed on a single one-way trajectory to maximum depth on which the tether is severed. A minimum of three moles is considered essential in providing replicated depth profile data sets. Furthermore, the mission has a specific technology demonstration component to it in providing a basic demonstration of water-mining as part of an in-situ resource utilisation validation programme - this will be achieved using zeolite caps deployed at the top of each borehole. There are a number of robotics issues inherent in this proposal. First, the micro-rover traverse requires extensive onboard navigation capabilities - we are investigating the use of the elastic loop mobility system for surface negotiation and potential fields as the mode of near-autonomous navigation. Second, the single direction mole trajectory will require a sophisticated onboard expert system to quick-look analyse depth profile data to make decisions on the control of the mole. The Vanguard mission represents a low-cost robotic Mars mission with a high scientific return and a significant demonstration of robotic technologies required for future Mars missions. We are currently proposing Vanguard as an Aurora Arrow mission to complement the Aurora ExoMars flagship mission.

Pyrolysis and hydrolysis of mixed polymer waste comprising polyethylene-terephthalate and polyethylene to sequentially recover [monomers

DOEpatents

Evans, R.J.; Chum, H.L.

1998-10-13

A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feed stream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feed stream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Pyrolysis and hydrolysis of mixed polymer waste comprising polyethyleneterephthalate and polyethylene to sequentially recover

DOEpatents

Evans, Robert J.; Chum, Helena L.

1998-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Combining selection valve and mixing chamber for nanoflow gradient generation: Toward developing a liquid chromatography cartridge coupled with mass spectrometer for protein and peptide analysis.

PubMed

Chen, Apeng; Lu, Joann J; Gu, Congying; Zhang, Min; Lynch, Kyle B; Liu, Shaorong

2015-08-05

Toward developing a micro HPLC cartridge, we have recently built a high-pressure electroosmotic pump (EOP). However, we do not recommend people to use this pump to deliver an organic solvent directly, because it often makes the pump rate unstable. We have experimented several approaches to address this issue, but none of them are satisfactory. Here, we develop an innovative approach to address this issue. We first create an abruption (a dead-volume) within a fluid conduit. We then utilize an EOP to withdraw, via a selection valve, a train of eluent solutions having decreasing eluting power into the fluid conduit. When these solutions are further aspirated through the dead-volume, these solutions are partially mixed, smoothening concentration transitions between two adjacent eluent solutions. As these solutions are pushed back, through the dead-volume again, a smooth gradient profile is formed. In this work, we characterize this scheme for gradient formation, and we incorporate this approach with a high-pressure EOP, a nanoliter injection valve, and a capillary column, yielding a micro HPLC system. We then couple this micro HPLC with an electrospray ionization - mass spectrometer for peptide and protein separations and identifications. Copyright © 2015 Elsevier B.V. All rights reserved.

MEMS in Space Systems

NASA Technical Reports Server (NTRS)

Lyke, J. C.; Michalicek, M. A.; Singaraju, B. K.

1995-01-01

Micro-electro-mechanical systems (MEMS) provide an emerging technology that has the potential for revolutionizing the way space systems are designed, assembled, and tested. The high launch costs of current space systems are a major determining factor in the amount of functionality that can be integrated in a typical space system. MEMS devices have the ability to increase the functionality of selected satellite subsystems while simultaneously decreasing spacecraft weight. The Air Force Phillips Laboratory (PL) is supporting the development of a variety of MEMS related technologies as one of several methods to reduce the weight of space systems and increase their performance. MEMS research is a natural extension of PL research objectives in micro-electronics and advanced packaging. Examples of applications that are under research include on-chip micro-coolers, micro-gyroscopes, vibration sensors, and three-dimensional packaging technologies to integrate electronics with MEMS devices. The first on-orbit space flight demonstration of these and other technologies is scheduled for next year.

Using speech for mode selection in control of multifunctional myoelectric prostheses.

PubMed

Fang, Peng; Wei, Zheng; Geng, Yanjuan; Yao, Fuan; Li, Guanglin

2013-01-01

Electromyogram (EMG) recorded from residual muscles of limbs is considered as suitable control information for motorized prostheses. However, in case of high-level amputations, the residual muscles are usually limited, which may not provide enough EMG for flexible control of myoelectric prostheses with multiple degrees of freedom of movements. Here, we proposed a control strategy, where the speech signals were used as additional information and combined with the EMG signals to realize more flexible control of multifunctional prostheses. By replacing the traditional "sequential mode-switching (joint-switching)", the speech signals were used to select a mode (joint) of the prosthetic arm, and then the EMG signals were applied to determine a motion class involved in the selected joint and to execute the motion. Preliminary results from three able-bodied subjects and one transhumeral amputee demonstrated the proposed strategy could achieve a high mode-selection rate and enhance the operation efficiency, suggesting the strategy may improve the control performance of commercial myoelectric prostheses.

Sequential alterations in the micro-localization of catalase in mouse liver after treatment with hypolipidemic drugs.

PubMed

Klucis, E; Crane, D; Masters, C

1984-11-01

A comparative study has been carried out on the micro-localization of catalase in mouse tissues subsequent to treatment with a representative range of hypolipidemic drugs. A commonality of effect was shown by clofibrate (ethyl-alpha-p-chlorophenoxyisobutyrate), Wy-14,643 (4-chloro-6-[2,3 xylidino)-2-pyrimidinylthio] acetic acid), RMI-15,414 (5-tetradecyloxy-2-furancarboxylic acid) and aspirin (acetyl salicylic acid), in that treatments with each of these drugs was associated with the release of peroxisomal catalase into the cytoplasmic compartment of liver and kidney. It was also noticeable that this increased cytosolic activity was characterized by the presence of an 'aged' form of the enzyme with different mobility and activity characteristics to that of the peroxisomal enzyme. Possible molecular bases for these effects and their relationship to peroxisomal biogenesis are discussed.

Evaluation and improvement of micro-surfacing mix design method and modelling of asphalt emulsion mastic in terms of filler-emulsion interaction

NASA Astrophysics Data System (ADS)

Robati, Masoud

This Doctorate program focuses on the evaluation and improving the rutting resistance of micro-surfacing mixtures. There are many research problems related to the rutting resistance of micro-surfacing mixtures that still require further research to be solved. The main objective of this Ph.D. program is to experimentally and analytically study and improve rutting resistance of micro-surfacing mixtures. During this Ph.D. program major aspects related to the rutting resistance of micro-surfacing mixtures are investigated and presented as follow: 1) evaluation of a modification of current micro-surfacing mix design procedures: On the basis of this effort, a new mix design procedure is proposed for type III micro-surfacing mixtures as rut-fill materials on the road surface. Unlike the current mix design guidelines and specification, the new mix design is capable of selecting the optimum mix proportions for micro-surfacing mixtures; 2) evaluation of test methods and selection of aggregate grading for type III application of micro-surfacing: Within the term of this study, a new specification for selection of aggregate grading for type III application of micro-surfacing is proposed; 3) evaluation of repeatability and reproducibility of micro-surfacing mixture design tests: In this study, limits for repeatability and reproducibility of micro-surfacing mix design tests are presented; 4) a new conceptual model for filler stiffening effect on asphalt mastic of micro-surfacing: A new model is proposed, which is able to establish limits for minimum and maximum filler concentrations in the micro-surfacing mixture base on only the filler important physical and chemical properties; 5) incorporation of reclaimed asphalt pavement and post-fabrication asphalt shingles in micro-surfacing mixture: The effectiveness of newly developed mix design procedure for micro-surfacing mixtures is further validated using recycled materials. The results present the limits for the use of RAP and RAS amount in micro-surfacing mixtures; 6) new colored micro-surfacing formulations with improved durability and performance: The significant improvement of around 45% in rutting resistance of colored and conventional micro-surfacing mixtures is achieved through employing low penetration grade bitumen polymer modified asphalt emulsion stabilized using nanoparticles.

Full Intelligent Cancer Classification of Thermal Breast Images to Assist Physician in Clinical Diagnostic Applications

PubMed Central

Lashkari, AmirEhsan; Pak, Fatemeh; Firouzmand, Mohammad

2016-01-01

Breast cancer is the most common type of cancer among women. The important key to treat the breast cancer is early detection of it because according to many pathological studies more than 75% – 80% of all abnormalities are still benign at primary stages; so in recent years, many studies and extensive research done to early detection of breast cancer with higher precision and accuracy. Infra-red breast thermography is an imaging technique based on recording temperature distribution patterns of breast tissue. Compared with breast mammography technique, thermography is more suitable technique because it is noninvasive, non-contact, passive and free ionizing radiation. In this paper, a full automatic high accuracy technique for classification of suspicious areas in thermogram images with the aim of assisting physicians in early detection of breast cancer has been presented. Proposed algorithm consists of four main steps: pre-processing & segmentation, feature extraction, feature selection and classification. At the first step, using full automatic operation, region of interest (ROI) determined and the quality of image improved. Using thresholding and edge detection techniques, both right and left breasts separated from each other. Then relative suspected areas become segmented and image matrix normalized due to the uniqueness of each person's body temperature. At feature extraction stage, 23 features, including statistical, morphological, frequency domain, histogram and Gray Level Co-occurrence Matrix (GLCM) based features are extracted from segmented right and left breast obtained from step 1. To achieve the best features, feature selection methods such as minimum Redundancy and Maximum Relevance (mRMR), Sequential Forward Selection (SFS), Sequential Backward Selection (SBS), Sequential Floating Forward Selection (SFFS), Sequential Floating Backward Selection (SFBS) and Genetic Algorithm (GA) have been used at step 3. Finally to classify and TH labeling procedures, different classifiers such as AdaBoost, Support Vector Machine (SVM), k-Nearest Neighbors (kNN), Naïve Bayes (NB) and probability Neural Network (PNN) are assessed to find the best suitable one. These steps are applied on different thermogram images degrees. The results obtained on native database showed the best and significant performance of the proposed algorithm in comprise to the similar studies. According to experimental results, GA combined with AdaBoost with the mean accuracy of 85.33% and 87.42% on the left and right breast images with 0 degree, GA combined with AdaBoost with mean accuracy of 85.17% on the left breast images with 45 degree and mRMR combined with AdaBoost with mean accuracy of 85.15% on the right breast images with 45 degree, and also GA combined with AdaBoost with a mean accuracy of 84.67% and 86.21%, on the left and right breast images with 90 degree, are the best combinations of feature selection and classifier for evaluation of breast images. PMID:27014608

Immediately sequential bilateral cataract surgery: advantages and disadvantages.

PubMed

Singh, Ranjodh; Dohlman, Thomas H; Sun, Grace

2017-01-01

The number of cataract surgeries performed globally will continue to rise to meet the needs of an aging population. This increased demand will require healthcare systems and providers to find new surgical efficiencies while maintaining excellent surgical outcomes. Immediately sequential bilateral cataract surgery (ISBCS) has been proposed as a solution and is increasingly being performed worldwide. The purpose of this review is to discuss the advantages and disadvantages of ISBCS. When appropriate patient selection occurs and guidelines are followed, ISBCS is comparable with delayed sequential bilateral cataract surgery in long-term patient satisfaction, visual acuity and complication rates. In addition, the risk of bilateral postoperative endophthalmitis and concerns of poorer refractive outcomes have not been supported by the literature. ISBCS is cost-effective for the patient, healthcare payors and society, but current reimbursement models in many countries create significant financial barriers for facilities and surgeons. As demand for cataract surgery rises worldwide, ISBCS will become increasingly important as an alternative to delayed sequential bilateral cataract surgery. Advantages include potentially decreased wait times for surgery, patient convenience and cost savings for healthcare payors. Although they are comparable in visual acuity and complication rates, hurdles that prevent wide adoption include liability concerns as ISBCS is not an established standard of care, economic constraints for facilities and surgeons and inability to fine-tune intraocular lens selection in the second eye. Given these considerations, an open discussion regarding the advantages and disadvantages of ISBCS is important for appropriate patient selection.

Shape-morphing composites with designed micro-architectures

DOE PAGES

Rodriguez, Jennifer N.; Zhu, Cheng; Duoss, Eric B.; ...

2016-06-15

Shape memory polymers (SMPs) are attractive materials due to their unique mechanical properties, including high deformation capacity and shape recovery. SMPs are easier to process, lightweight, and inexpensive compared to their metallic counterparts, shape memory alloys. However, SMPs are limited to relatively small form factors due to their low recovery stresses. Lightweight, micro-architected composite SMPs may overcome these size limitations and offer the ability to combine functional properties (e.g., electrical conductivity) with shape memory behavior. Fabrication of 3D SMP thermoset structures via traditional manufacturing methods is challenging, especially for designs that are composed of multiple materials within porous microarchitectures designedmore » for specific shape change strategies, e.g. sequential shape recovery. We report thermoset SMP composite inks containing some materials from renewable resources that can be 3D printed into complex, multi-material architectures that exhibit programmable shape changes with temperature and time. Through addition of fiber-based fillers, we demonstrate printing of electrically conductive SMPs where multiple shape states may induce functional changes in a device and that shape changes can be actuated via heating of printed composites. As a result, the ability of SMPs to recover their original shapes will be advantageous for a broad range of applications, including medical, aerospace, and robotic devices.« less

Real-time 2D spatially selective MRI experiments: Comparative analysis of optimal control design methods.

PubMed

Maximov, Ivan I; Vinding, Mads S; Tse, Desmond H Y; Nielsen, Niels Chr; Shah, N Jon

2015-05-01

There is an increasing need for development of advanced radio-frequency (RF) pulse techniques in modern magnetic resonance imaging (MRI) systems driven by recent advancements in ultra-high magnetic field systems, new parallel transmit/receive coil designs, and accessible powerful computational facilities. 2D spatially selective RF pulses are an example of advanced pulses that have many applications of clinical relevance, e.g., reduced field of view imaging, and MR spectroscopy. The 2D spatially selective RF pulses are mostly generated and optimised with numerical methods that can handle vast controls and multiple constraints. With this study we aim at demonstrating that numerical, optimal control (OC) algorithms are efficient for the design of 2D spatially selective MRI experiments, when robustness towards e.g. field inhomogeneity is in focus. We have chosen three popular OC algorithms; two which are gradient-based, concurrent methods using first- and second-order derivatives, respectively; and a third that belongs to the sequential, monotonically convergent family. We used two experimental models: a water phantom, and an in vivo human head. Taking into consideration the challenging experimental setup, our analysis suggests the use of the sequential, monotonic approach and the second-order gradient-based approach as computational speed, experimental robustness, and image quality is key. All algorithms used in this work were implemented in the MATLAB environment and are freely available to the MRI community. Copyright © 2015 Elsevier Inc. All rights reserved.

High-resolution three-dimensional magnetic resonance imaging of mouse lung in situ.

PubMed

Scadeng, Miriam; Rossiter, Harry B; Dubowitz, David J; Breen, Ellen C

2007-01-01

This study establishes a method for high-resolution isotropic magnetic resonance (MR) imaging of mouse lungs using tracheal liquid-instillation to remove MR susceptibility artifacts. C57BL/6J mice were instilled sequentially with perfluorocarbon and phosphate-buffered saline to an airway pressure of 10, 20, or 30 cm H2O. Imaging was performed in a 7T MR scanner using a 2.5-cm Quadrature volume coil and a 3-dimensional (3D) FLASH imaging sequence. Liquid-instillation removed magnetic susceptibility artifacts and allowed lung structure to be viewed at an isotropic resolution of 78-90 microm. Instilled liquid and modeled lung volumes were well correlated (R = 0.92; P < 0.05) and differed by a constant tissue volume (220 +/- 92 microL). 3D image renderings allowed differences in structural dimensions (volumes and areas) to be accurately measured at each inflation pressure. These data demonstrate the efficacy of pulmonary liquid instillation for in situ high-resolution MR imaging of mouse lungs for accurate measurement of pulmonary airway, parenchymal, and vascular structures.

Sn/Be Sequentially co-doped Hematite Photoanodes for Enhanced Photoelectrochemical Water Oxidation: Effect of Be2+ as co-dopant

PubMed Central

Annamalai, Alagappan; Lee, Hyun Hwi; Choi, Sun Hee; Lee, Su Yong; Gracia-Espino, Eduardo; Subramanian, Arunprabaharan; Park, Jaedeuk; Kong, Ki-jeong; Jang, Jum Suk

2016-01-01

For ex-situ co-doping methods, sintering at high temperatures enables rapid diffusion of Sn4+ and Be2+ dopants into hematite (α–Fe2O3) lattices, without altering the nanorod morphology or damaging their crystallinity. Sn/Be co-doping results in a remarkable enhancement in photocurrent (1.7 mA/cm2) compared to pristine α–Fe2O3 (0.7 mA/cm2), and Sn4+ mono-doped α-Fe2O3 photoanodes (1.0 mA/cm2). From first-principles calculations, we found that Sn4+ doping induced a shallow donor level below the conduction band minimum, which does not contribute to increase electrical conductivity and photocurrent because of its localized nature. Additionally, Sn4+-doping induce local micro-strain and a decreased Fe-O bond ordering. When Be2+ was co-doped with Sn4+-doped α–Fe2O3 photoanodes, the conduction band recovered its original state, without localized impurities peaks, also a reduction in micro-strain and increased Fe-O bond ordering is observed. Also the sequence in which the ex-situ co-doping is carried out is very crucial, as Be/Sn co-doping sequence induces many under-coordinated O atoms resulting in a higher micro-strain and lower charge separation efficiency resulting undesired electron recombination. Here, we perform a detailed systematic characterization using XRD, FESEM, XPS and comprehensive electrochemical and photoelectrochemical studies, along with sophisticated synchrotron diffraction studies and extended X-ray absorption fine structure. PMID:27005757

Antitumor effect of cordycepin (3'-deoxyadenosine) on mouse melanoma and lung carcinoma cells involves adenosine A3 receptor stimulation.

PubMed

Nakamura, Kazuki; Yoshikawa, Noriko; Yamaguchi, Yu; Kagota, Satomi; Shinozuka, Kazumasa; Kunitomo, Masaru

2006-01-01

An attempt was made to elucidate the molecular targetfor the antitumor effects of cordycepin (3'-deoxyadenosine) using non-selective and selective adenosine A1, A2a, A2b and A3 receptor agonists and antagonists. Although adenosine and 2'-deoxyadenosine (up to 100 microM) had no effect, cordycepin showed remarkable inhibitory effects on the growth curves of B16-BL6 mouse melanoma (IC50= 39 microM) and mouse Lewis lung carcinoma (IC50 = 48 microM) cell lines in vitro. Among the adenosine receptor agonists and antagonists used (up to 100 microM), only 2-chloro-N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (Cl-IB-MECA), a selective adenosine A3 receptor agonist, notably inhibited the growth of both mouse tumor cell lines (B16-BL6; IC50 = 5 microM, LLC; 14 microM). In addition, the tumor growth inhibitory effect of cordycepin was antagonized by 3-ethyl 5-benzyl 2-methyl-6-phenyl-4-phenylethynyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191), a selective adenosine A3 receptor antagonist. These results suggest that cordycepin exerts inhibitory effects on the growth of mouse melanoma and lung carcinoma cells by stimulating adenosine A3 receptors on tumor cells.

Nanostructured refractory thin films for solar applications

NASA Astrophysics Data System (ADS)

Ollier, E.; Dunoyer, N.; Dellea, O.; Szambolics, H.

2014-08-01

Selective solar absorbers are key elements of all solar thermal systems. Solar thermal panels and Concentrated Solar Power (CSP) systems aim respectively at producing heat and electricity. In both cases, a surface receives the solar radiation and is designed to have the highest optical absorption (lowest optical reflectivity) of the solar radiation in the visible wavelength range where the solar intensity is the highest. It also has a low emissivity in the infrared (IR) range in order to avoid radiative thermal losses. Current solutions in the state of the art usually consist in deposited interferential thin films or in cermets [1]. Structured surfaces have been proposed and have been simulated because they are supposed to be more efficient when the solar radiation is not normal to the receiving surface and because they could potentially be fabricated with refractory materials able to sustain high operating temperatures. This work presents a new method to fabricate micro/nanostructured surfaces on molybdenum (refractory metal with a melting temperature of 2623°C). This method now allows obtaining a refractory selective surface with an excellent optical selectivity and a very high absorption in the visible range. This high absorption performance was obtained by achieving a double structuration at micro and nano scales thanks to an innovative process flow.

Monitoring tumor metastases and osteolytic lesions with bioluminescence and micro CT imaging.

PubMed

Lim, Ed; Modi, Kshitij; Christensen, Anna; Meganck, Jeff; Oldfield, Stephen; Zhang, Ning

2011-04-14

Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence imaging using IVIS Spectrum was employed to monitor the distribution and development of the tumor cells following the delivery procedure including DLIT reconstruction to measure the tumor signal and its location. Development of metastatic lesions to the bone tissues triggers osteolytic activity and lesions to tibia and femur were evaluated longitudinally using micro CT. Imaging was performed using a Quantum FX micro CT system with fast imaging and low X-ray dose. The low radiation dose allows multiple imaging sessions to be performed with a cumulative X-ray dosage far below LD50. A mouse imaging shuttle device was used to sequentially image the mice with both IVIS Spectrum and Quantum FX achieving accurate animal positioning in both the bioluminescence and CT images. The optical and CT data sets were co-registered in 3-dimentions using the Living Image 4.1 software. This multi-mode approach allows close monitoring of tumor growth and development simultaneously with osteolytic activity.

Hybrid 3D-2D printing for bone scaffolds fabrication

NASA Astrophysics Data System (ADS)

Seleznev, V. A.; Prinz, V. Ya

2017-02-01

It is a well-known fact that bone scaffold topography on micro- and nanometer scale influences the cellular behavior. Nano-scale surface modification of scaffolds allows the modulation of biological activity for enhanced cell differentiation. To date, there has been only a limited success in printing scaffolds with micro- and nano-scale features exposed on the surface. To improve on the currently available imperfect technologies, in our paper we introduce new hybrid technologies based on a combination of 2D (nano imprint) and 3D printing methods. The first method is based on using light projection 3D printing and simultaneous 2D nanostructuring of each of the layers during the formation of the 3D structure. The second method is based on the sequential integration of preliminarily created 2D nanostructured films into a 3D printed structure. The capabilities of the developed hybrid technologies are demonstrated with the example of forming 3D bone scaffolds. The proposed technologies can be used to fabricate complex 3D micro- and nanostructured products for various fields.

Programmable spectrometer using MOEMs devices for space applications

NASA Astrophysics Data System (ADS)

Viard, Thierry; Buisset, Christophe; Rejeaunier, Xavier; Zamkotsian, Frédéric; Venancio, Luis M.

2017-11-01

A new class of spectrometer can be designed using programmable components such as MOEMS which enable to tune the beam in spectral width and central wavelength. It becomes possible to propose for space applications a spectrometer with programmable resolution and adjustable spectral bandwidth. The proposed way to tune the output beam is to use the diffraction effect with the so-called PMDG (Programmable Micro Diffraction Gratings ) diffractive MEMS. In that case, small moving structures can form programmable gratings, diffracting or not the incoming light. In the proposed concept, the MOEMS is placed in the focal plane of a first diffracting stage (using a grating for instance). With such implementation, the MOEMS component can be used to select some wavelengths (for instance by reflecting them) and to switch-off the others (for instance by diffracting them). A second diffracting stage is used to recombine the beam composed by all the selected wavelengths. It becomes then possible to change and adjust the filter in λ and Δλ. This type of implementation is very interesting for space applications (Astronomy, Earth observation, planetary observation). Firstly because it becomes possible to tune the filtering function quasi instantaneously. And secondly because the focal plane dimension can be reduced to a single detector (for application without field of view) or to a linear detector instead of a 2D matrix detector (for application with field of view) thanks to a sequential acquisition of the signal.

Polyacrylonitrile-Derived Sponge-Like Micro/Macroporous Carbon for Selective CO2 Separation.

PubMed

Guo, Li-Ping; Hu, Qing-Tao; Zhang, Peng; Li, Wen-Cui; Lu, An-Hui

2018-06-12

CO 2 capture under a dynamical flow situation requires adsorbents possessing balanced proportion of macropores as diffusion path and micropores as adsorption reservoir. However, the construction of interconnected micro-/macropores structure coupled with abundant nitrogen species into one carbon skeleton remains a challenge. Here, we report a new approach to prepare sponge-like carbon with a well-developed micro-/macroporous structure and enriched nitrogen species through aqueous phase polymerization of acrylonitrile in the presence of graphene oxide. The tension stress caused by the uniform thermal shrinkage of polyacrylonitrile during the pyrolysis together with the favorable flexibility of graphene oxide sheets are responsible for the formation of the sponge-like morphology. The synergistic effect of micro-/macroporous framework and rich CO 2 -philic site enables such carbon to decrease resistance to mass transfer and show high CO 2 dynamic selectivity over N 2 (454) and CH 4 (11), as well as good CO 2 capacity at 298 K under low CO 2 partial pressure (0.17 bar, a typical CO 2 partial pressure in flue gas). The above attributes make this porous carbon a promising candidate for CO 2 capture from flue gas, methane sources and other relevant applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The water kefir grain inoculum determines the characteristics of the resulting water kefir fermentation process.

PubMed

Laureys, D; De Vuyst, L

2017-03-01

To investigate the influence of the water kefir grain inoculum on the characteristics of the water kefir fermentation process. Three water kefir fermentation processes were started with different water kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile and metabolite production course. The inoculum determined the water kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these micro-organisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii and Saccharomyces cerevisiae were always present and may be the key micro-organisms during water kefir fermentation. Low water kefir grain growth was associated with small grains with high viable counts of micro-organisms, fast fermentation and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. The water kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key micro-organisms was always present during fermentation. This study allows a rational selection of a water kefir grain inoculum. © 2016 The Society for Applied Microbiology.

Analysis of optical route in a micro high-speed magneto-optic switch

NASA Astrophysics Data System (ADS)

Weng, Zihua; Yang, Guoguang; Huang, Yuanqing; Chen, Zhimin; Zhu, Yun; Wu, Jinming; Lin, Shufen; Mo, Weiping

2005-02-01

A novel micro high-speed 2x2 magneto-optic switch and its optical route, which is used in high-speed all-optical communication network, is designed and analyzed in this paper. The study of micro high-speed magneto-optic switch mainly involves the optical route and high-speed control technique design. The optical route design covers optical route design of polarization in optical switch, the performance analysis and material selection of magneto-optic crystal and magnetic path design in Faraday rotator. The research of high-speed control technique involves the study of nanosecond pulse generator, high-speed magnetic field and its control technique etc. High-speed current transients from nanosecond pulse generator are used to switch the magnetization of the magneto-optic crystal, which propagates a 1550nm optical beam. The optical route design schemes and electronic circuits of high-speed control technique are both simulated on computer and test by the experiments respectively. The experiment results state that the nanosecond pulse generator can output the pulse with rising edge time 3~35ns, voltage amplitude 10~90V and pulse width 10~100ns. Under the control of CPU singlechip, the optical beam can be stably switched and the switching time is less than 1μs currently.

Externally resonated linear microvibromotor for microassembly

NASA Astrophysics Data System (ADS)

Saitou, Kazuhiro; Wou, Soungjin J.

1998-10-01

A new design of a linear micro vibromotor for on-substrate fine positioning of micro-scale components is presented where a micro linear slider is actuated by vibratory impacts exerted by micro cantilever impacters. These micro cantilever impacters are selectively resonated by shaking the entire substrate with a piezoelectric vibrator, requiring no need for built-in driving mechanisms such as electrostatic comb actuators as reported previously. This selective resonance of the micro cantilever impacters via an external vibration energy field provides with a very simple means of controlling forward and backward motion of the micro linear slider, facilitating assembly and disassembly of a micro component on a substrate. The double-V beam suspension design is employed in the micro cantilever impacters for larger displacement in the lateral direction while achieving higher stiffness in the transversal direction. An analytical model of the device is derived in order to obtain, through the Simulated Annealing algorithm, an optimal design which maximizes translation speed of the linear slider at desired external input frequencies. Prototypes of the externally-resonated linear micro vibromotor are fabricated using the three-layer polysilicon surface micro machining process provided by the MCNC MUMPS service.

Candida zemplinina can reduce acetic acid produced by Saccharomyces cerevisiae in sweet wine fermentations.

PubMed

Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca; Cocolin, Luca

2012-03-01

In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ~0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response.

μ-'Diving suit' for liquid-phase high-Q resonant detection.

PubMed

Yu, Haitao; Chen, Ying; Xu, Pengcheng; Xu, Tiegang; Bao, Yuyang; Li, Xinxin

2016-03-07

A resonant cantilever sensor is, for the first time, dressed in a water-proof 'diving suit' for real-time bio/chemical detection in liquid. The μ-'diving suit' technology can effectively avoid not only unsustainable resonance due to heavy liquid-damping, but also inevitable nonspecific adsorption on the cantilever body. Such a novel technology ensures long-time high-Q resonance of the cantilever in solution environment for real-time trace-concentration bio/chemical detection and analysis. After the formation of the integrated resonant micro-cantilever, a patterned photoresist and hydrophobic parylene thin-film are sequentially formed on top of the cantilever as sacrificial layer and water-proof coat, respectively. After sacrificial-layer release, an air gap is formed between the parylene coat and the cantilever to protect the resonant cantilever from heavy liquid damping effect. Only a small sensing-pool area, located at the cantilever free-end and locally coated with specific sensing-material, is exposed to the liquid analyte for gravimetric detection. The specifically adsorbed analyte mass can be real-time detected by recording the frequency-shift signal. In order to secure vibration movement of the cantilever and, simultaneously, reject liquid leakage from the sensing-pool region, a hydrophobic parylene made narrow slit structure is designed surrounding the sensing-pool. The anti-leakage effect of the narrow slit and damping limited resonance Q-factor are modelled and optimally designed. Integrated with electro-thermal resonance excitation and piezoresistive frequency readout, the cantilever is embedded in a micro-fluidic chip to form a lab-chip micro-system for liquid-phase bio/chemical detection. Experimental results show the Q-factor of 23 in water and longer than 20 hours liquid-phase continuous working time. Loaded with two kinds of sensing-materials at the sensing-pools, two types of sensing chips successfully show real-time liquid-phase detection to ppb-level organophosphorous pesticide of acephate and E.coli DH5α in PBS, respectively. The proposed method fundamentally solves the long-standing problem of being unable to operate a resonant micro-sensor in liquid well.

The Effects of a Modified Treatment Package with and without Feeder Modeling on One Child's Acceptance of Novel Foods

ERIC Educational Resources Information Center

Seiverling, Laura; Harclerode, Whitney; Williams, Keith

2014-01-01

The purpose of this study was to examine if sequential presentation with feeder modeling would lead to an increase in bites accepted of new foods compared to sequential presentation without feeder modeling in a typically developing 4-year-old boy with food selectivity. The participant's acceptance of novel foods increased both in the modeling and…

Design of a micro-Wankel rotary engine for MEMS fabrication

NASA Astrophysics Data System (ADS)

Jiang, Kyle C.; Prewett, Philip D.; Ward, M. C. L.; Tian, Y.; Yang, H.

2001-04-01

This paper presents the design of a micro Wankel engine for deep etching micro fabrication. The micro engine design is part of a research program in progress to develop a micro actuator to supply torque for driving micro machines. To begin with, the research work concentrates on the micro Wankel engine powered by liquid CO2. Then, a Wankel internal combustion engines will be investigated. The Wankel engine is a planetary rotation engine. It is selected because of its largely 2D structure which is suitable for lithographic processes. The engine has been simplified and redesigned to suit the fabrication processes. In particular, the fuel inlet has been moved to the top cover of the housing from the side, and the outlet is made as a groove on the housing, so that the both parts can be etched. A synchronization valve is mounted on the engine to control the supply of CO2. One of advantages of the micro engines is their high energy density compared with batteries. A research study has been conducted in comparing energy densities of commonly used fuels. It shows that the energy densities of fuels for combustion engines are 10 - 30 times higher than that of batteries. The deigns of the micro Wankel engines have been tested for verification by finite element analysis, CAD assembly, and construction of a prototype, which proves the design is valid.

Sample Size Calculations for Micro-randomized Trials in mHealth

PubMed Central

Liao, Peng; Klasnja, Predrag; Tewari, Ambuj; Murphy, Susan A.

2015-01-01

The use and development of mobile interventions are experiencing rapid growth. In “just-in-time” mobile interventions, treatments are provided via a mobile device and they are intended to help an individual make healthy decisions “in the moment,” and thus have a proximal, near future impact. Currently the development of mobile interventions is proceeding at a much faster pace than that of associated data science methods. A first step toward developing data-based methods is to provide an experimental design for testing the proximal effects of these just-in-time treatments. In this paper, we propose a “micro-randomized” trial design for this purpose. In a micro-randomized trial, treatments are sequentially randomized throughout the conduct of the study, with the result that each participant may be randomized at the 100s or 1000s of occasions at which a treatment might be provided. Further, we develop a test statistic for assessing the proximal effect of a treatment as well as an associated sample size calculator. We conduct simulation evaluations of the sample size calculator in various settings. Rules of thumb that might be used in designing a micro-randomized trial are discussed. This work is motivated by our collaboration on the HeartSteps mobile application designed to increase physical activity. PMID:26707831

Anaesthetic modulation of nicotinic ion channel kinetics in bovine chromaffin cells.

PubMed Central

Charlesworth, P; Richards, C D

1995-01-01

1. We have investigated the action of the anaesthetics methoxyflurane, methohexitone and etomidate on the nicotinic acetylcholine receptor channel of bovine adrenal chromaffin cells using the whole cell patch clamp technique. 2. Spectral analysis of macroscopic currents evoked by 25 microM carbachol revealed that each of the agents tested reduced the lifetime of the channel open state in a dose-dependent manner. The whole cell current was inhibited in a concentration-dependent fashion by each agent. 3. Channel gating parameters were calculated from single channel studies and the results used to test models explaining the modulation of nicotinic acetylcholine receptor channels by anaesthetics. 4. Each of the agents studied reduced the mean channel open time in a concentration-dependent manner. Anaesthetic concentrations reducing mean open time by 50% were: 370 microM methoxyflurane, 30 microM methohexitone or 23 microM etomidate. 5. Methohexitone and etomidate produced an increase in the number of brief closures within bursts, while no such increase was observed with methoxyflurane. Despite these inter-burst gaps, mean burst length was reduced by each of the agents tested. 6. It is concluded that a simple sequential blocking model fails to account for the action of these anaesthetics. An extended model, in which blocked channels can close, may be applicable. PMID:7773553

Fast encryption of RGB color digital images using a tweakable cellular automaton based schema

NASA Astrophysics Data System (ADS)

Faraoun, Kamel Mohamed

2014-12-01

We propose a new tweakable construction of block-enciphers using second-order reversible cellular automata, and we apply it to encipher RGB-colored images. The proposed construction permits a parallel encryption of the image content by extending the standard definition of a block cipher to take into account a supplementary parameter used as a tweak (nonce) to control the behavior of the cipher from one region of the image to the other, and hence avoid the necessity to use slow sequential encryption's operating modes. The proposed construction defines a flexible pseudorandom permutation that can be used with efficacy to solve the electronic code book problem without the need to a specific sequential mode. Obtained results from various experiments show that the proposed schema achieves high security and execution performances, and enables an interesting mode of selective area decryption due to the parallel character of the approach.

Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

PubMed Central

Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

2015-01-01

Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic process completely detoxified all the selected textile azo dyes, further efforts should be made to implement such methods for large scale dye wastewater treatment technologies. PMID:26417357

Feature Selection based on Machine Learning in MRIs for Hippocampal Segmentation

NASA Astrophysics Data System (ADS)

Tangaro, Sabina; Amoroso, Nicola; Brescia, Massimo; Cavuoti, Stefano; Chincarini, Andrea; Errico, Rosangela; Paolo, Inglese; Longo, Giuseppe; Maglietta, Rosalia; Tateo, Andrea; Riccio, Giuseppe; Bellotti, Roberto

2015-01-01

Neurodegenerative diseases are frequently associated with structural changes in the brain. Magnetic resonance imaging (MRI) scans can show these variations and therefore can be used as a supportive feature for a number of neurodegenerative diseases. The hippocampus has been known to be a biomarker for Alzheimer disease and other neurological and psychiatric diseases. However, it requires accurate, robust, and reproducible delineation of hippocampal structures. Fully automatic methods are usually the voxel based approach; for each voxel a number of local features were calculated. In this paper, we compared four different techniques for feature selection from a set of 315 features extracted for each voxel: (i) filter method based on the Kolmogorov-Smirnov test; two wrapper methods, respectively, (ii) sequential forward selection and (iii) sequential backward elimination; and (iv) embedded method based on the Random Forest Classifier on a set of 10 T1-weighted brain MRIs and tested on an independent set of 25 subjects. The resulting segmentations were compared with manual reference labelling. By using only 23 feature for each voxel (sequential backward elimination) we obtained comparable state-of-the-art performances with respect to the standard tool FreeSurfer.

Instant Integrated Ultradeep Quantitative-structural Membrane Proteomics Discovered Post-translational Modification Signatures for Human Cys-loop Receptor Subunit Bias.

PubMed

Zhang, Xi

2016-12-01

Neurotransmitter ligand-gated ion channels (LGICs) are widespread and pivotal in brain functions. Unveiling their structure-function mechanisms is crucial to drive drug discovery, and demands robust proteomic quantitation of expression, post-translational modifications (PTMs) and dynamic structures. Yet unbiased digestion of these modified transmembrane proteins-at high efficiency and peptide reproducibility-poses the obstacle. Targeting both enzyme-substrate contacts and PTMs for peptide formation and detection, we devised flow-and-detergent-facilitated protease and de-PTM digestions for deep sequencing (FDD) method that combined omni-compatible detergent, tandem immobilized protease/PNGase columns, and Cys-selective reduction/alkylation, to achieve streamlined ultradeep peptide preparation within minutes not days, at high peptide reproducibility and low abundance-bias. FDD transformed enzyme-protein contacts into equal catalytic travel paths through enzyme-excessive columns regardless of protein abundance, removed products instantly preventing inhibition, tackled intricate structures via sequential multiple micro-digestions along the flow, and precisely controlled peptide formation by flow rate. Peptide-stage reactions reduced steric bias; low contamination deepened MS/MS scan; distinguishing disulfide from M oxidation and avoiding gain/loss artifacts unmasked protein-endogenous oxidation states. Using a recent interactome of 285-kDa human GABA type A receptor, this pilot study validated FDD platform's applicability to deep sequencing (up to 99% coverage), H/D-exchange and TMT-based structural mapping. FDD discovered novel subunit-specific PTM signatures, including unusual nontop-surface N-glycosylations, that may drive subunit biases in human Cys-loop LGIC assembly and pharmacology, by redefining subunit/ligand interfaces and connecting function domains. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Synthesis of the PPARbeta/delta-selective agonist GW501516 and C4-thiazole-substituted analogs.

PubMed

Pereira, Raquel; Gaudon, Claudine; Iglesias, Beatriz; Germain, Pierre; Gronemeyer, Hinrich; de Lera, Angel R

2006-01-01

Sequential, position-selective, Pd-catalyzed cross-coupling reactions of 2,4-dibromo-5-hydroxymethylthiazole provided the scaffold for the synthesis of GW501516, the most potent PPARbeta/delta agonist yet described, and equally selective analogs at the thiazole-C4 position.

Sequential ozone advanced oxidation and biological oxidation processes to remove selected pharmaceutical contaminants from an urban wastewater.

PubMed

Espejo, Azahara; Aguinaco, Almudena; García-Araya, J F; Beltrán, Fernando J

2014-01-01

Sequential treatments consisting in a chemical process followed by a conventional biological treatment, have been applied to remove mixtures of nine contaminants of pharmaceutical type spiked in a primary sedimentation effluent of a municipal wastewater. Combinations of ozone, UVA black light (BL) and Fe(III) or Fe₃O₄ catalysts constituted the chemical systems. Regardless of the Advanced Oxidation Process (AOP), the removal of pharmaceutical compounds was achieved in 1 h of reaction, while total organic carbon (TOC) only diminished between 3.4 and 6%. Among selected ozonation systems to be implemented before the biological treatment, the application of ozone alone in the pre-treatment stage is recommended due to the increase of the biodegradability observed. The application of ozone followed by the conventional biological treatment leads high TOC and COD removal rates, 60 and 61%, respectively, and allows the subsequent biological treatment works with shorter hydraulic residence time (HRT). Moreover, the influence of the application of AOPs before and after a conventional biological process was compared, concluding that the decision to take depends on the characterization of the initial wastewater with pharmaceutical compounds.

Inhibitory effect of strychnine on acetylcholine receptor activation in bovine adrenal medullary chromaffin cells.

PubMed Central

Kuijpers, G A; Vergara, L A; Calvo, S; Yadid, G

1994-01-01

1. Strychnine, which is known as a potent and selective antagonist of the inhibitory glycine receptor in the central nervous system, inhibits the nicotinic stimulation of catecholamine release from bovine cultured adrenal chromaffin cells in a concentration-dependent (1-100 microM) manner. At 10 microM nicotine, the IC50 value for strychnine is approximately 30 microM. Strychnine also inhibits the nicotine-induced membrane depolarization and increase in intracellular Ca2+ concentration. 2. The inhibitory action of strychnine is reversible and is selective for nicotinic stimulation, with no effect observed on secretion elicited by a high external K+ concentration, histamine or angiotensin II. 3. Strychnine competes with nicotine in its effect, but not modify the apparent positive cooperatively of the nicotine binding sites. In the absence of nicotine, strychnine has no effect on catecholamine release. Glycine does not affect catecholamine release nor the inhibitory action of strychnine on this release. 4. These results suggest that strychnine interacts with the agonist binding site of the nicotinic acetylcholine receptor in chromaffin cells, thus exerting a pharmacological effect independently of the glycine receptor. PMID:7834198

Methods for Selecting Phage Display Antibody Libraries.

PubMed

Jara-Acevedo, Ricardo; Diez, Paula; Gonzalez-Gonzalez, Maria; Degano, Rosa Maria; Ibarrola, Nieves; Gongora, Rafael; Orfao, Alberto; Fuentes, Manuel

2016-01-01

The selection process aims sequential enrichment of phage antibody display library in clones that recognize the target of interest or antigen as the library undergoes successive rounds of selection. In this review, selection methods most commonly used for phage display antibody libraries have been comprehensively described. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Dissociation of metabolic and hemodynamic levodopa responses in the 6-hydroxydopamine rat model.

PubMed

Lerner, Renata P; Bimpisidis, Zisis; Agorastos, Stergiani; Scherrer, Sandra; Dewey, Stephen L; Cenci, M Angela; Eidelberg, David

2016-12-01

Dissociation of vasomotor and metabolic responses to levodopa has been observed in human subjects with Parkinson's disease (PD) studied with PET and in autoradiograms from 6-hydroxydopamine (6-OHDA) rat. In both species, acute levodopa administration was associated with increases in basal ganglia cerebral blood flow (CBF) with concurrent reductions in cerebral metabolic rate (CMR) for glucose in the same brain regions. In this study, we used a novel dual-tracer microPET technique to measure CBF and CMR levodopa responses in the same animal. Rats with unilateral 6-OHDA or sham lesion underwent sequential 15 O-water (H 2 15 O) and 18 F-fluorodeoxyglucose (FDG) microPET to map CBF and CMR following the injection of levodopa or saline. A subset of animals was separately scanned under ketamine/xylazine and isoflurane to compare the effects of these anesthetics. Regardless of anesthetic agent, 6-OHDA animals exhibited significant dissociation of vasomotor (ΔCBF) and metabolic (ΔCMR) responses to levodopa, with stereotyped increases in CBF and reductions in CMR in the basal ganglia ipsilateral to the dopamine lesion. No significant changes were seen in sham-lesioned animals. These data faithfully recapitulate analogous dissociation effects observed previously in human PD subjects scanned sequentially during levodopa infusion. This approach may have utility in the assessment of new drugs targeting the exaggerated regional vasomotor responses seen in human PD and in experimental models of levodopa-induced dyskinesia. Copyright © 2016 Elsevier Inc. All rights reserved.

A preclinical rodent model of acute radiation-induced lung injury after ablative focal irradiation reflecting clinical stereotactic body radiotherapy.

PubMed

Hong, Zhen-Yu; Lee, Hae-June; Choi, Won Hoon; Lee, Yoon-Jin; Eun, Sung Ho; Lee, Jung Il; Park, Kwangwoo; Lee, Ji Min; Cho, Jaeho

2014-07-01

In a previous study, we established an image-guided small-animal micro-irradiation system mimicking clinical stereotactic body radiotherapy (SBRT). The goal of this study was to develop a rodent model of acute phase lung injury after ablative irradiation. A radiation dose of 90 Gy was focally delivered to the left lung of C57BL/6 mice using a small animal stereotactic irradiator. At days 1, 3, 5, 7, 9, 11 and 14 after irradiation, the lungs were perfused with formalin for fixation and paraffin sections were stained with hematoxylin and eosin (H&E) and Masson's trichrome. At days 7 and 14 after irradiation, micro-computed tomography (CT) images of the lung were taken and lung functional measurements were performed with a flexiVent™ system. Gross morphological injury was evident 9 days after irradiation of normal lung tissues and dynamic sequential events occurring during the acute phase were validated by histopathological analysis. CT images of the mouse lungs indicated partial obstruction located in the peripheral area of the left lung. Significant alteration in inspiratory capacity and tissue damping were detected on day 14 after irradiation. An animal model of radiation-induced lung injury (RILI) in the acute phase reflecting clinical stereotactic body radiotherapy was established and validated with histopathological and functional analysis. This model enhances our understanding of the dynamic sequential events occurring in the acute phase of radiation-induced lung injury induced by ablative dose focal volume irradiation.

Genome-wide sequencing and quantification of circulating microRNAs for dogs with congestive heart failure secondary to myxomatous mitral valve degeneration.

PubMed

Jung, SeungWoo; Bohan, Amy

2018-02-01

OBJECTIVE To characterize expression profiles of circulating microRNAs via genome-wide sequencing for dogs with congestive heart failure (CHF) secondary to myxomatous mitral valve degeneration (MMVD). ANIMALS 9 healthy client-owned dogs and 8 age-matched client-owned dogs with CHF secondary to MMVD. PROCEDURES Blood samples were collected before administering cardiac medications for the management of CHF. Isolated microRNAs from plasma were classified into microRNA libraries and subjected to next-generation sequencing (NGS) for genome-wide sequencing analysis and quantification of circulating microRNAs. Quantitative reverse transcription PCR (qRT-PCR) assays were used to validate expression profiles of differentially expressed circulating microRNAs identified from NGS analysis of dogs with CHF. RESULTS 326 microRNAs were identified with NGS analysis. Hierarchical analysis revealed distinct expression patterns of circulating microRNAs between healthy dogs and dogs with CHF. Results of qRT-PCR assays confirmed upregulation of 4 microRNAs (miR-133, miR-1, miR-let-7e, and miR-125) and downregulation of 4 selected microRNAs (miR-30c, miR-128, miR-142, and miR-423). Results of qRT-PCR assays were highly correlated with NGS data and supported the specificity of circulating microRNA expression profiles in dogs with CHF secondary to MMVD. CONCLUSIONS AND CLINICAL RELEVANCE These results suggested that circulating microRNA expression patterns were unique and could serve as molecular biomarkers of CHF in dogs with MMVD.

Mechanisms of morphine enhancement of spontaneous seizure activity.

PubMed

Saboory, Ehsan; Derchansky, Miron; Ismaili, Mohammed; Jahromi, Shokrollah S; Brull, Richard; Carlen, Peter L; El Beheiry, Hossam

2007-12-01

High-dose opioid therapy can precipitate seizures; however, the mechanism of such a dangerous adverse effect remains poorly understood. The aim of our study was to determine whether the neuroexcitatory activity of high-dose morphine is mediated by selective stimulation of opioid receptors. Mice hippocampi were resected intact and bathed in low magnesium artificial cerebrospinal fluid to induce spontaneous seizure-like events recorded from CA1 neurons. Application of morphine had a biphasic effect on the recorded spontaneous seizure-like events. In a low concentration (10 microM), morphine depressed electrographic seizure activity. Higher morphine concentrations (30 and 100 microM) enhanced seizure activity in an apparent dose-dependent manner. Naloxone, a nonselective opiate antagonist blocked the proconvulsant action of morphine. Selective mu and kappa opiate receptor agonists and antagonists enhanced and suppressed the spontaneous seizure activity, respectively. On the contrary, delta opioid receptor ligands did not have an effect. The proseizure effect of morphine is mediated through selective stimulation of mu and kappa opiate receptors but not the activation of the delta receptor system. The observed dose-dependent mechanism of morphine neuroexcitation underscores careful adjustment and individualized opioid dosing in the clinical setting.

Comparison of 3 selective media for enumeration of Bacillus cereus in several food matrixes.

PubMed

Chon, Jung-Whan; Song, Kwang-Young; Kim, Hyunsook; Seo, Kun-Ho

2014-12-01

In this study, we compared the inclusivity, exclusivity, recoverability, and selectivity of the 3 selective agars (mannitol yolk polymyxin B agar [MYPA], polymyxin pyruvate egg yolk mannitol bromothymol blue agar [PEMBA], and Brillance Bacillus cereus agar [BBC agar]) for Bacillus cereus (B. cereus) from pure culture and several food samples. BBC agar showed greater exclusivity and selectivity in pure culture and in foods with high background flora, respectively; however, all the tested media showed similar recoverability (P > 0.05) of B. cereus in pure culture and in most foods. Our results suggest that BBC agar could be useful to enumerate B. cereus from, in particular, food matrixes with high background competing micro flora. © 2014 Institute of Food Technologists®

Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoupin, Stanislav; Antipov, Sergey; Butler, James E.

Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configurationmore » and data analysis using rocking-curve topography. In conclusion, the variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.« less

Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics.

PubMed

Stoupin, Stanislav; Antipov, Sergey; Butler, James E; Kolyadin, Alexander V; Katrusha, Andrey

2016-09-01

Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking-curve topography. The variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.

Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics

DOE PAGES

Stoupin, Stanislav; Antipov, Sergey; Butler, James E.; ...

2016-08-10

Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configurationmore » and data analysis using rocking-curve topography. In conclusion, the variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.« less

Design of micro-ring optical sensors and circuits for integration on optical printed circuit boards (O-PCBs)

NASA Astrophysics Data System (ADS)

Lee, El-Hang; Lee, Hyun S.; Lee, S. G.; O, B. H.; Park, S. G.; Kim, K. H.

2007-05-01

We report on the design of micro-ring resonator optical sensors for integration on what we call optical printed circuit boards (O-PCBs). The objective is to realize application-specific O-PCBs, either on hard board or on flexible board, by integrating micro/nano-scale optical sensors for compact, light-weight, low-energy, high-speed, intelligent, and environmentally friendly processing of information. The O-PCBs consist of two-dimensional planar arrays of micro/nano-scale optical wires, circuits and devices that are interconnected and integrated to perform the functions of sensing and then storing, transporting, processing, switching, routing and distributing optical signals that have been collected by means of sensors. For fabrication, the polymer and organic optical wires and waveguides are first fabricated on a board and are used to interconnect and integrate sensors and other micro/ nano-scale photonic devices. Here, in our study, we focus on the sensors based on the micro-ring structures. We designed bio-sensors using silicon based micro-ring resonator. We investigate the characteristics such as sensitivity and selectivity (or quality factor) of micro-ring resonator for their use in bio-sensing application. We performed simulation studies on the quality factor of micro-ring resonators by varying the radius of the ring resonators and the separation between adjacent waveguides. We introduce the effective coupling coefficient as a realistic value to describe the strength of the coupling in micro-ring resonators.

Structural drift: the population dynamics of sequential learning.

PubMed

Crutchfield, James P; Whalen, Sean

2012-01-01

We introduce a theory of sequential causal inference in which learners in a chain estimate a structural model from their upstream "teacher" and then pass samples from the model to their downstream "student". It extends the population dynamics of genetic drift, recasting Kimura's selectively neutral theory as a special case of a generalized drift process using structured populations with memory. We examine the diffusion and fixation properties of several drift processes and propose applications to learning, inference, and evolution. We also demonstrate how the organization of drift process space controls fidelity, facilitates innovations, and leads to information loss in sequential learning with and without memory.

Increasing the speed of tumour diagnosis during surgery with selective scanning Raman microscopy

NASA Astrophysics Data System (ADS)

Kong, Kenny; Rowlands, Christopher J.; Varma, Sandeep; Perkins, William; Leach, Iain H.; Koloydenko, Alexey A.; Pitiot, Alain; Williams, Hywel C.; Notingher, Ioan

2014-09-01

One of the main challenges in cancer surgery is ensuring that all tumour cells are removed during surgery, while sparing as much healthy tissue as possible. Histopathology, the gold-standard technique for cancer diagnosis, is often impractical for intra-operative use because of the time-consuming tissue preparation procedures (sectioning and staining). Raman micro-spectroscopy is a powerful technique that can discriminate between tumours and healthy tissues with high accuracy, based entirely on intrinsic chemical differences. However, raster-scanning Raman micro-spectroscopy is a slow imaging technique that typically requires data acquisition times as long as several days for typical tissue samples obtained during surgery (1 × 1 cm2) - in particular when high signal-to-noise ratio spectra are required to ensure accurate diagnosis. In this paper we present two techniques based on selective sampling Raman micro-spectroscopy that can overcome these limitations. In selective sampling, information regarding the spatial features of the tissue, either measured by an alternative optical technique or estimated in real-time from the Raman spectra, can be used to drastically reduce the number of Raman spectra required for diagnosis. These sampling strategies allowed diagnosis of basal cell carcinoma in skin tissue samples excised during Mohs micrographic surgery faster than frozen section histopathology, and two orders of magnitude faster than previous techniques based on raster-scanning Raman microscopy. Further development of these techniques may help during cancer surgery by providing a fast and objective way for surgeons to ensure the complete removal of tumour cells while sparing as much healthy tissue as possible.

Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).

PubMed

Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S

2004-03-07

The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.

Micro- and Nano-scale Technologies for Delivery into Adherent Cells

PubMed Central

Kang, Wonmo; McNaughton, Rebecca L.; Espinosa, Horacio D.

2016-01-01

Several recent micro- and nano-technologies have provided novel methods for biological studies of adherent cells because the small features of these new biotools provide unique capabilities for accessing cells without the need for suspension or lysis. These novel approaches have enabled gentle, yet effective delivery of molecules into specific adhered target cells, with unprecedented spatial resolution. Here we review recent progress in the development of these technologies with an emphasis on in vitro delivery into adherent cells utilizing mechanical penetration or electroporation. We discuss major advantages and limitations of these approaches and propose possible strategies for improvements. Finally, we discuss the impact of these technologies on biological research concerning cell-specific temporal studies, e.g., non-destructive sampling and analysis of intracellular molecules. Need For Techniques To Study Adherent Cells A mechanistic understanding of cell biology is often limited by both the complexity of the processes and limitations of commonly available research tools that lack temporal or spatial resolution. The lack of tools capable of providing cell-specific, non-destructive biomolecular delivery and analysis is a particular barrier for advancing fundamental discoveries of cell heterogeneity, single-cell behavior within a complex environment, and the mechanisms that govern disease states, responses to drugs or other stimuli, and differentiation of stem cells. To gain new mechanistic understanding, advances in methods for precise intracellular delivery and non-destructive biochemical analyses of non-secretory molecules (e.g., mRNA and proteins) are greatly needed so that individual cells can be experimentally controlled and repeatedly analyzed over time and/or within a particular location of the cell. For example, developing neurons must undergo a series of sequential changes in gene expression to achieve a mature phenotype; hence, understanding the process will require the ability to accurately monitor the sequence of intracellular events, within individual cells, in a non-destructive manner. In addition, neuronal maturation is influenced by interactions with surrounding cells and with extracellular matrix, so it is necessary to be able to simultaneously monitor events occurring in multiple cells that are interacting with each other and with the matrix. While the requirements are challenging, these experimental capabilities would provide unprecedented insight into the determinants of both the timing of cellular processes and their phenotype, the principles of cell heterogeneity, and the role of cell-cell communication in homogeneous cell populations and co-cultures. Because most cells adhere to a substrate or to other cells during their growth or differentiation [1], it is advantageous for new technologies to be capable of accessing adhered cells to avoid the need to disrupt cell processes by suspension and replating. Several technologies for studying adhered cells are currently being developed, and due to the need for individual cell access and non-destructive probing, micro- and nano-technologies are a natural choice because they interact with cells at the appropriate length scale, reduce the working volume of expensive reagents, require less time and space for replicates, allow for automation and integration of sequential analyses, enable portability, and reduce waste [2, 3]. Here we present an overview of recently developed micro- and nano-tools, with a focus on trends in intracellular delivery for in vitro studies of adhered cells, and highlight major advantages/disadvantages of these technologies with respect to features such as individual cell selectivity, spatial resolution, non-destructive cell analysis, and potential for high throughput or automation. Finally, we discuss the exciting promise for these technologies to cause a paradigm shift in biological research by providing methods to study cells over time at the individual cell level. PMID:27287927

Micro Ring Grating Spectrometer with Adjustable Aperture

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor); Choi, Sang H. (Inventor)

2012-01-01

A spectrometer includes a micro-ring grating device having coaxially-aligned ring gratings for diffracting incident light onto a target focal point, a detection device for detecting light intensity, one or more actuators, and an adjustable aperture device defining a circular aperture. The aperture circumscribes a target focal point, and directs a light to the detection device. The aperture device is selectively adjustable using the actuators to select a portion of a frequency band for transmission to the detection device. A method of detecting intensity of a selected band of incident light includes directing incident light onto coaxially-aligned ring gratings of a micro-ring grating device, and diffracting the selected band onto a target focal point using the ring gratings. The method includes using an actuator to adjust an aperture device and pass a selected portion of the frequency band to a detection device for measuring the intensity of the selected portion.

Development, validation and application of a micro-liquid chromatography-tandem mass spectrometry based method for simultaneous quantification of selected protein biomarkers of endothelial dysfunction in murine plasma.

PubMed

Suraj, Joanna; Kurpińska, Anna; Olkowicz, Mariola; Niedzielska-Andres, Ewa; Smolik, Magdalena; Zakrzewska, Agnieszka; Jasztal, Agnieszka; Sitek, Barbara; Chlopicki, Stefan; Walczak, Maria

2018-02-05

The objective of this study was to develop and validate the method based on micro-liquid chromatography-tandem mass spectrometry (microLC/MS-MRM) for simultaneous determination of adiponectin (ADN), von Willebrand factor (vWF), soluble form of vascular cell adhesion molecule 1 (sVCAM-1), soluble form of intercellular adhesion molecule 1 (sICAM-1) and syndecan-1 (SDC-1) in mouse plasma. The calibration range was established from 2.5pmol/mL to 5000pmol/mL for ADN; 5pmol/mL to 5000pmol/mL for vWF; 0.375pmol/mL to 250pmol/mL for sVCAM-1 and sICAM-1; and 0.25pmol/mL to 250pmol/mL for SDC-1. The method was applied to measure the plasma concentration of selected proteins in mice fed high-fat diet (HFD), and revealed the pro-thrombotic status by increased concentration of vWF (1.31±0.17 nmol/mL (Control) vs 1.98±0.09 nmol/mL (HFD), p <0.05) and the dysregulation of adipose tissue metabolism by decreased concentration of ADN (0.62±0.08 nmol/mL (Control) vs 0.37±0.06 nmol/mL (HFD), p <0.05). In conclusion, the microLC/MS-MRM-based method allows for reliable measurements of selected protein biomarkers of endothelial dysfunction in mouse plasma. Copyright © 2017 Elsevier B.V. All rights reserved.

MicroRNAs associated with muscle growth and fillet quality in rainbow trout

USDA-ARS?s Scientific Manuscript database

Selection for improved muscle growth and quality phenotypes requires understanding of post-transcriptional gene-regulation mechanisms. To investigate role of microRNAs in muscle post-transcriptional gene regulation, RNA-seq was used to identify differential expression in microRNAs and SNPs in microR...

Microfluidic biosensing systems. Part I. Development and optimisation of enzymatic chemiluminescent micro-biosensors based on silicon microchips.

PubMed

Davidsson, Richard; Genin, Frédéric; Bengtsson, Martin; Laurell, Thomas; Emnéus, Jenny

2004-10-01

Chemiluminescent (CL) enzyme-based flow-through microchip biosensors (micro-biosensors) for detection of glucose and ethanol were developed for the purpose of monitoring real-time production and release of glucose and ethanol from microchip immobilised yeast cells. Part I of this study focuses on the development and optimisation of the micro-biosensors in a microfluidic sequential injection analysis (microSIA) system. Glucose oxidase (GOX) or alcohol oxidase (AOX) was co-immobilised with horseradish peroxidase (HRP) on porous silicon flow through microchips. The hydrogen peroxide produced from oxidation of the corresponding analyte (glucose or ethanol) took part in the chemiluminescent (CL) oxidation of luminol catalysed by HRP enhanced by addition of p-iodophenol (PIP). All steps in the microSIA system, including control of syringe pump, multiposition valve (MPV) and data readout, were computer controlled. The influence of flow rate and luminol- and PIP concentration were investigated using a 2(3)-factor experiment using the GOX-HRP sensor. It was found that all estimated single factors and the highest order of interaction were significant. The optimum was found at 250 microM luminol and 150 microM PIP at a flow rate of 18 microl min(-1), the latter as a compromise between signal intensity and analysis time. Using the optimised system settings one sample was processed within 5 min. Two different immobilisation chemistries were investigated for both micro-biosensors based on 3-aminopropyltriethoxsilane (APTS)- or polyethylenimine (PEI) functionalisation followed by glutaraldehyde (GA) activation. GOX-HRP micro-biosensors responded linear in a log-log format within the range 10-1000 microM glucose. Both had an operational stability of at least 8 days, but the PEI-GOX-HRP sensor was more sensitive. The AOX-HRP micro-biosensors responded linear (log-log) in the range between 1 and 10 mM ethanol, but the PEI-AOX-HRP sensor was in general more sensitive. Both sensors had an operational stability of at least 8 h, but with a half-life of 2-3 days.

SR high-speed K-edge subtraction angiography in the small animal (abstract)

NASA Astrophysics Data System (ADS)

Takeda, T.; Akisada, M.; Nakajima, T.; Anno, I.; Ueda, K.; Umetani, K.; Yamaguchi, C.

1989-07-01

To assess the ability of the high-speed K-edge energy subtraction system which was made at beamline 8C of Photon Factory, Tsukuba, we performed an animal experiment. Rabbits were used for the intravenous K-edge subtraction angiography. In this paper, the actual images of the artery obtained by this system, are demonstrated. The high-speed K-edge subtraction system consisted of movable silicon (111) monocrystals, II-ITV, and digital memory system. Image processing was performed by 68000-IP computer. The monochromatic x-ray beam size was 50×60 mm. Photon energy above and below iodine K edge was changed within 16 ms and 32 frames of images were obtained sequentially. The rabbits were anaesthetized by phenobarbital and a 5F catheter was inserted into inferior vena cava via the femoral vein. 1.5 ml/kg of contrast material (Conlaxin H) was injected at the rate of 0.5 ml/kg/s. TV images were obtained 3 s after the starting point of injection. By using this system, the clear K-edge subtracted images were obtained sequentially as a conventional DSA system. The quality of the images were better than that obtained by DSA. The dynamical blood flow was analyzed, and the best arterial image could be selected from the sequential images. The structures of aortic arch, common carotid arteries, right subclavian artery, and internal thoracic artery were obtained at the chest. Both common carotid arteries and vertebral arteries were recorded at the neck. The diameter of about 0.3-0.4 mm artery could be clearly revealed. The high-speed K-edge subtraction system demonstrates the very sharp arterial images clearly and dynamically.

In situ nanostructure formation of (micro-hydroxo)bis(micro-carboxylato) diruthenium units in nafion membrane and its utilization for selective reduction of nitrosonium ion in aqueous medium.

PubMed

Kumar, Annamalai Senthil; Tanase, Tomoaki; Iida, Masayasu

2007-01-16

Nanostructured molecular film containing the (micro-hydroxo)bis(micro-carboxylato) diruthenium(III) units, [RuIII2(micro-OH)(micro-CH3COO)2(HBpz3)2]+ ({RuIII2(micro-OH)}), was prepared by an in situ conversion of its micro-oxo precursor, [RuIII2(micro-O)(micro-CH3COO)2(HBpz3)2] ({RuIII2(micro-O)}), in a Nafion membrane matrix, where HBpz3 is hydrotris(1-pyrazolyl)borate. The conversion procedure results in fine nanoparticle aggregates of the {RuIII2(micro-OH)} units in the Nafion membrane (Nf-{RuIII2(micro-OH)}), where an average particle size (4.1 +/- 2.3 nm) is close to the Nafion's cluster dimension of approximately 4 nm. Chemically modified electrodes by using the Nafion molecular membrane films (Nf-{RuIII2(micro-OH)}-MMFEs) were further developed on ITO/glass and glassy carbon electrode (GCE) surfaces, and a selective reduction of nitrosonium ion (NO+), presumably through reaction of a {RuIIRuIII(micro-OH)} mixed-valence state with HNO2, was demonstrated without interference by molecular oxygen in an acidic aqueous solution. The Nf-{RuIII2(micro-OH)}-MMFEs are stable even in a physiological condition (pH 7), where the naked {RuIII2(-OH)} complex is readily transformed into its deprotonated {RuIII2(micro-O)} form, demonstrating an unusual stabilizing effects for the {RuIII2(micro-OH)} unit by the Nafion cluster environment.

Ionic liquid-impregnated agarose film two-phase micro-electrodriven membrane extraction (IL-AF-μ-EME) for the analysis of antidepressants in water samples.

PubMed

Mohamad Hanapi, Nor Suhaila; Sanagi, Mohd Marsin; Ismail, Abd Khamim; Wan Ibrahim, Wan Aini; Saim, Nor'ashikin; Wan Ibrahim, Wan Nazihah

2017-03-01

The aim of this study was to investigate and apply supported ionic liquid membrane (SILM) in two-phase micro-electrodriven membrane extraction combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) for pre-concentration and determination of three selected antidepressant drugs in water samples. A thin agarose film impregnated with 1-hexyl-3-methylimidazolium hexafluorophosphate, [C 6 MIM] [PF 6 ], was prepared and used as supported ionic liquid membrane between aqueous sample solution and acceptor phase for extraction of imipramine, amitriptyline and chlorpromazine. Under the optimized extraction conditions, the method provided good linearity in the range of 1.0-1000μgL -1 , good coefficients of determination (r 2 =0.9974-0.9992) and low limits of detection (0.1-0.4μgL -1 ). The method showed high enrichment factors in the range of 110-150 and high relative recoveries in the range of 88.2-111.4% and 90.9-107.0%, for river water and tap water samples, respectively with RSDs of ≤7.6 (n=3). This method was successfully applied to the determination of the drugs in river and tap water samples. It is envisaged that the SILM improved the perm-selectivity by providing a pathway for targeted analytes which resulted in rapid extraction with high degree of selectivity and high enrichment factor. Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tfaily, Malak M.; Chu, Rosalie K.; Toyoda, Jason

A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO2. The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition.more » In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H2O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl3) mixture, or acetonitrile (ACN) and CHCl3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample is used for each solvent type. Furthermore, a comparison of SOM composition from the different sample types revealed that our sequential protocol allows for ecosystem comparisons based on the diversity of compounds present, which in turn could provide new insights about source and processing of organic compounds in different soil and sediment types.« less

Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry.

PubMed

Tfaily, Malak M; Chu, Rosalie K; Toyoda, Jason; Tolić, Nikola; Robinson, Errol W; Paša-Tolić, Ljiljana; Hess, Nancy J

2017-06-15

A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO 2 . The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition. In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H 2 O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl 3 ) mixture, or acetonitrile (ACN) and CHCl 3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample is used for each solvent type. Furthermore, a comparison of SOM composition from the different sample types revealed that our sequential protocol allows for ecosystem comparisons based on the diversity of compounds present, which in turn could provide new insights about source and processing of organic compounds in different soil and sediment types. Copyright © 2017 Elsevier B.V. All rights reserved.

4-Alkylated homoibotenic acid (HIBO) analogues: versatile pharmacological agents with diverse selectivity profiles towards metabotropic and ionotropic glutamate receptor subtypes.

PubMed

Madsen, Ulf; Pickering, Darryl S; Nielsen, Birgitte; Bräuner-Osborne, Hans

2005-01-01

4-Alkylated analogues of homoibotenic acid (HIBO) have previously shown high potency and selectivity at ionotropic and metabotropic glutamic acid receptor (iGluR and mGluR) subtypes. Compounds with different selectivity profiles are valuable pharmacological tools for neuropharmacological studies, and the series of 4-alkyl-HIBO analogues have been extended in this paper in the search for versatile agents. Pharmacological characterization of five new analogues, branched and unbranched 4-alkyl-HIBO analogues, have been carried out. The present compounds are all weak antagonists at Group I mGluRs (mGluR1 and 5) presenting only small differences in potencies (Ki values ranging from 89 to 670 microM). Affinities were studied at native and cloned iGluRs, and the compounds described show preference for the AMPA receptor subtypes GluR1 and 2 over GluR3 and 4. However, compared to previous 4-alkyl-HIBO analogues, these compounds show a remarkably high affinity for the Kain preferring subtype GluR5. The observed GluR5 affinities were either similar or higher compared to their GluR1 and 2 affinity. Isopropyl-HIBO showed the highest affinity for GluR5 (Ki=0.16 microM), and represents a unique compound with high affinity towards the three subtypes GluR1, 2 and 5. In general, these compounds represent new selectivity profiles compared to previously reported Glu receptor analogues.

Functional characterization of tachykinin NK1 receptors in the mouse uterus.

PubMed

Patak, Eva; Pennefather, Jocelyn N; Fleming, Anna; Story, Margot E

2002-12-01

1. Contractility studies were undertaken to determine the nature of the receptors mediating responses to tachykinins in uteri of oestrogen-treated mice. 2. In the presence of thiorphan (3 microM), captopril (10 microM), and bestatin (10 microM), substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) produced concentration-related contractions of uterine preparations. The order of potency was SP > or =NKA>NKB. 3. Neither atropine (0.1 microM) nor l-NOLA (100 microM), nor indomethacin (10 microM) alone or in combination with either ranitidine (10 microM) or mepyramine (10 microM), affected responses to SP. These findings indicate that SP actions are not mediated or modulated through the release of acetylcholine, nitric oxide, prostanoids or histamine. 4. In the presence of peptidase inhibitors, the tachykinin NK(1) receptor-selective agonist [Sar(9)Met(O(2))(11)]SP, produced a concentration-dependent contractile effect. The tachykinin NK(2) and NK(3) receptor-selective agonists [Lys(5)MeLeu(9)Nle(10)]NKA(4-10) and [MePhe(7)]NKB were relatively inactive. The potencies of SP analogues in which Glu replaced Gln(5) and/or Gln(6) were similar to that of SP. 5. The tachykinin NK(1) receptor-selective antagonist, SR140333 (10 nM), alone or combined with the tachykinin NK(2) receptor-selective antagonist, SR48968 (10 nM), shifted log concentration curves to SP, NKA and NKB to the right. SR140333 (10 nM) reduced the effect of [Sar(9)Met(O(2))(11)]SP. SR48968 did not affect responses to SP or [Sar(9)Met(O(2))(11)]SP, but reduced the effect of higher concentrations of NKA and shifted the log concentration-response curve to NKB to the right. The tachykinin NK(3) receptor-selective antagonist, SR 142801 (0.3 microM), had little effect on responses to SP and NKB. 6. We conclude that the tachykinin NK(1) receptor mediates contractile effects of SP, NKA and NKB and [Sar(9)Met(O(2))(11)]SP in myometrium from the oestrogen-primed mouse. The tachykinin NK(2) receptor may also participate in the responses to NKA and NKB.

Forced guidance and distribution of practice in sequential information processing.

NASA Technical Reports Server (NTRS)

Decker, L. R.; Rogers, C. A., Jr.

1973-01-01

Distribution of practice and forced guidance were used in a sequential information-processing task in an attempt to increase the capacity of human information-processing mechanisms. A reaction time index of the psychological refractory period was used as the response measure. Massing of practice lengthened response times while forced guidance shortened them. Interpretation was in terms of load reduction upon the response-selection stage of the information-processing system.-

Enantioselective Construction of 3-Hydroxypiperidine Scaffolds by Sequential Action of Light and Rhodium upon N-Allylglyoxylamides.

PubMed

Ishida, Naoki; Nečas, David; Masuda, Yusuke; Murakami, Masahiro

2015-06-15

3-Hydroxypiperidine scaffolds were enantioselectively constructed in an atom-economical way by sequential action of light and rhodium upon N-allylglyoxylamides. In a formal sense, the allylic C-H bond was selectively cleaved and enantioselectively added across the ketonic carbonyl group with migration of the double bond (carbonyl-ene-type reaction). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acetylcholine, carbachol, and GABA induce no detectable change in the length of isolated outer hair cells.

PubMed

Bobbin, R P; Fallon, M; Puel, J L; Bryant, G; Bledsoe, S C; Zajic, G; Schacht, J

1990-08-01

The mechanical and electrical properties of cochlear outer hair cells (OHCs) are suggested to modulate transduction by inner hair cells. These properties of OHCs are presumably regulated by efferent neurons which use several transmitters including acetylcholine (Ach) and gamma aminobutyric acid (GABA). Since it had been suggested that Ach causes isolated OHCs to shorten visibly, this study was designed to investigate whether GABA also alters the length of OHCs. OHCs were isolated from the guinea pig cochlea by mechanical dispersion after collagenase treatment. Cells were initially selected by strict morphological criteria. In addition they were only included in further studies if they attained a constant length during 10 min of superfusion with buffer solution. Neither GABA (20 microM: 100 microM), Ach (5 mM; 10 microM with 10 microM eserine) or carbachol (10 microM; 100 microM) altered OHC length when applied in iso-osmotic Hank's balanced salt solution (total number of cells tested, 72). If a change in length occurred it must have been smaller than 0.3 microns, our detection ability. In contrast, high potassium and variations in osmolarity changed hair cell length by 3-10% in agreement with other reports.

Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry.

PubMed

Merlo, Sabina; Poma, Paolo; Crisà, Eleonora; Faralli, Dino; Soldo, Marco

2017-02-25

In this work, we have applied optical low-coherence reflectometry (OLCR), implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis) as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time.

Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry

PubMed Central

Merlo, Sabina; Poma, Paolo; Crisà, Eleonora; Faralli, Dino; Soldo, Marco

2017-01-01

In this work, we have applied optical low-coherence reflectometry (OLCR), implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis) as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time. PMID:28245603

Selective cytotoxic effect of non-thermal micro-DBD plasma

NASA Astrophysics Data System (ADS)

Kwon, Byung-Su; Choi, Eun Ha; Chang, Boksoon; Choi, Jeong-Hyun; Kim, Kyung Sook; Park, Hun-Kuk

2016-10-01

Non-thermal plasma has been extensively researched as a new cancer treatment technology. We investigated the selective cytotoxic effects of non-thermal micro-dielectric barrier discharge (micro-DBD) plasma in cervical cancer cells. Two human cervical cancer cell lines (HeLa and SiHa) and one human fibroblast (HFB) cell line were treated with micro-DBD plasma. All cells underwent apoptotic death induced by plasma in a dose-dependent manner. The plasma showed selective inhibition of cell proliferation in cervical cancer cells compared to HFBs. The selective effects of the plasma were also observed between the different cervical cancer cell lines. Plasma treatment significantly inhibited the proliferation of SiHa cells in comparison to HeLa cells. The changes in gene expression were significant in the cervical cancer cells in comparison to HFBs. Among the cancer cells, apoptosis-related genes were significantly enriched in SiHa cells. These changes were consistent with the differential cytotoxic effects observed in different cell lines.

Detection of gastric cancer-associated microRNAs on microRNA microarray comparing pre- and post-operative plasma

PubMed Central

Konishi, H; Ichikawa, D; Komatsu, S; Shiozaki, A; Tsujiura, M; Takeshita, H; Morimura, R; Nagata, H; Arita, T; Kawaguchi, T; Hirashima, S; Fujiwara, H; Okamoto, K; Otsuji, E

2012-01-01

Background: Recently, it was reported that plasma microRNAs (miRNAs) are low-invasive useful biomarkers for cancer. We attempted to isolate gastric cancer (GC)-associated miRNAs comparing pre- and post-operative paired plasma, thereby excluding the possible effects of individual variability. Methods: This study was divided into four steps: (1) microarray analysis comparing pre- and post-operative plasma; (2) validation of candidate miRNAs by quantitative RT–PCR; (3) validation study of selected miRNAs using paired plasma; and (4) comparison of the levels of selected miRNAs in plasma between healthy controls and patients. Results: From the results of microarray analysis, nine candidate miRNAs the levels of which were markedly decreased in post-operative plasma were selected for further studies. After confirmation of their post-operative marked reduction, two candidate miRNAs, miR-451 and miR-486, were selected as plasma biomarkers, considering the abundance in plasma, and marked decrease in post-operative samples. In validation, the two miRNAs were found to decrease in post-operative plasma in 90 and 93% of patients (both P<0.01). In comparison with healthy controls, the levels of both miRNAs were found to be significantly higher in patients, and the area under the curve values were high at 0.96 and 0.92. Conclusion: Plasma miR-451 and miR-486 could be useful blood-based biomarkers for screening GC. PMID:22262318

Synthesis and exploration of novel curcumin analogues as anti-malarial agents.

PubMed

Mishra, Satyendra; Karmodiya, Krishanpal; Surolia, Namita; Surolia, Avadhesha

2008-03-15

Curcumin, a major yellow pigment and active component of turmeric, has been shown to possess anti-inflammatory and anti-cancer activities. Recent studies have indicated that curcumin inhibits chloroquine-sensitive (CQ-S) and chloroquine-resistant (CQ-R) Plasmodium falciparum growth in culture with an IC(50) of approximately 3.25 microM (MIC=13.2 microM) and IC(50) 4.21 microM (MIC=14.4 microM), respectively. In order to expand their potential as anti-malarials a series of novel curcumin derivatives were synthesized and evaluated for their ability to inhibit P. falciparum growth in culture. Several curcumin analogues examined show more effective inhibition of P. falciparum growth than curcumin. The most potent curcumin compounds 3, 6, and 11 were inhibitory for CQ-S P. falciparum at IC(50) of 0.48, 0.87, 0.92 microM and CQ-R P. falciparum at IC(50) of 0.45 microM, 0.89, 0.75 microM, respectively. Pyrazole analogue of curcumin (3) exhibited sevenfold higher anti-malarial potency against CQ-S and ninefold higher anti-malarial potency against CQ-R. Curcumin analogues described here represent a novel class of highly selective P. falciparum inhibitors and promising candidates for the design of novel anti-malarial agents.

Direct fluorescence polarization assay for the detection of glycopeptide antibiotics.

PubMed

Yu, Linliang; Zhong, Meng; Wei, Yinan

2010-08-15

Glycopeptide antibiotics are widely used in the treatment of infections caused by Gram-positive bacteria. They inhibit the biosynthesis of the bacterial cell wall through binding to the D-alanyl-D-alanine (D-Ala-D-Ala) terminal peptide of the peptidoglycan precursor. Taking advantage of this highly specific interaction, we developed a direct fluorescence polarization based method for the detection of glycopeptide antibiotics. Briefly, we labeled the acetylated tripeptide Ac-L-Lys-D-Ala-D-Ala-OH with a fluorophore to create a peptide probe. Using three glycopeptide antibiotics, vancomycin, teicoplanin, and telavancin, as model compounds, we demonstrated that the fluorescence polarization of the peptide probe increased upon binding to antibiotics in a concentration dependent manner. The dissociation constants (K(d)) between the peptide probes and the antibiotics were consistent with those reported between free d-Ala-d-Ala and the antibiotics in the literature. The assay is highly reproducible and selective toward glycopeptide antibiotics. Its detection limit and work concentration range are 0.5 microM and 0.5-4 microM for vancomycin, 0.25 microM and 0.25-2 microM for teicoplanin, and 1 microM and 1-8 microM for telavancin. Furthermore, we compared our assay in parallel with a commercial fluorescence polarization immunoassay (FPIA) kit in detecting teicoplanin spiked in human blood samples. The accuracy and precision of the two methods are comparable. We expect our assay to be useful in both research and clinical laboratories.

A One-Pot Tandem Strategy in Catalytic Asymmetric Vinylogous Aldol Reaction of Homoallylic Alcohols.

PubMed

Hou, Xufeng; Jing, Zhenzhong; Bai, Xiangbin; Jiang, Zhiyong

2016-06-27

Reported is a rationally-designed one-pot sequential strategy that allows homoallylic alcohols to be employed in a catalytic, asymmetric, direct vinylogous aldol reaction with a series of activated acyclic ketones, including trifluoromethyl ketones, γ-ketoesters, and α-keto phosphonates, in high yields (up to 95%) with excellent regio- and enantio-selectivity (up to 99% ee). This modular combination, including Jones oxidation and asymmetric organocatalysis, has satisfactory compatibility and reliability even at a 20 mmol scale, albeit without intermediary purification.

Speciation of mercury in sludge solids: washed sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bannochie, C. J.; Lourie, A. P.

2017-10-24

The objective of this applied research task was to study the type and concentration of mercury compounds found within the contaminated Savannah River Site Liquid Waste System (SRS LWS). A method of selective sequential extraction (SSE), developed by Eurofins Frontier Global Sciences1,2 and adapted by SRNL, utilizes an extraction procedure divided into seven separate tests for different species of mercury. In the SRNL’s modified procedure four of these tests were applied to a washed sample of high level radioactive waste sludge.

Advanced Nanoporous Materials for Micro-Gravimetric Sensing to Trace-Level Bio/Chemical Molecules

PubMed Central

Xu, Pengcheng; Li, Xinxin; Yu, Haitao; Xu, Tiegang

2014-01-01

Functionalized nanoporous materials have been developed recently as bio/chemical sensing materials. Due to the huge specific surface of the nano-materials for molecular adsorption, high hopes have been placed on gravimetric detection with micro/nano resonant cantilevers for ultra-sensitive sensing of low-concentration bio/chemical substances. In order to enhance selectivity of the gravimetric resonant sensors to the target molecules, it is crucial to modify specific groups onto the pore-surface of the nano-materials. By loading the nanoporous sensing material onto the desired region of the mass-type transducers like resonant cantilevers, the micro-gravimetric bio/chemical sensors can be formed. Recently, such micro-gravimetric bio/chemical sensors have been successfully applied for rapid or on-the-spot detection of various bio/chemical molecules at the trace-concentration level. The applicable nanoporous sensing materials include mesoporous silica, zeolite, nanoporous graphene oxide (GO) and so on. This review article focuses on the recent achievements in design, preparation, functionalization and characterization of advanced nanoporous sensing materials for micro-gravimetric bio/chemical sensing. PMID:25313499

Control of jasmonate biosynthesis and senescence by miR319 targets.

PubMed

Schommer, Carla; Palatnik, Javier F; Aggarwal, Pooja; Chételat, Aurore; Cubas, Pilar; Farmer, Edward E; Nath, Utpal; Weigel, Detlef

2008-09-23

Considerable progress has been made in identifying the targets of plant microRNAs, many of which regulate the stability or translation of mRNAs that encode transcription factors involved in development. In most cases, it is unknown, however, which immediate transcriptional targets mediate downstream effects of the microRNA-regulated transcription factors. We identified a new process controlled by the miR319-regulated clade of TCP (TEOSINTE BRANCHED/CYCLOIDEA/PCF) transcription factor genes. In contrast to other miRNA targets, several of which modulate hormone responses, TCPs control biosynthesis of the hormone jasmonic acid. Furthermore, we demonstrate a previously unrecognized effect of TCPs on leaf senescence, a process in which jasmonic acid has been proposed to be a critical regulator. We propose that miR319-controlled TCP transcription factors coordinate two sequential processes in leaf development: leaf growth, which they negatively regulate, and leaf senescence, which they positively regulate.

Kinetic studies of the inhibition of a human liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase isozyme by bile acids and anti-inflammatory drugs.

PubMed

Miyabe, Y; Amano, T; Deyashiki, Y; Hara, A; Tsukada, F

1995-01-01

We have investigated the steady-state kinetics for a cytosolic 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase isozyme of human liver and its inhibition by several bile acids and anti-inflammatory drugs such as indomethacin, flufemanic acid and naproxen. Initial velocity and product inhibition studies performed in the NADP(+)-linked (S)-1-indanol oxidation at pH 7.4 were consistent with a sequential ordered mechanism in which NADP+ binds first and leaves last. The bile acids and drugs, competitive inhibitors with respect to the alcohol substrate, exhibited uncompetitive inhibition with respect to the coenzyme, with Ki values less than 1 microM, whereas indomethacin exhibited noncompetitive inhibition (Ki < 24 microM). The kinetics of the inhibition by a mixture of the two inhibitors suggests that bile acids and drugs, except indomethacin, bind to overlapping sites at the active center of the enzyme-coenzyme binary complex.

Bismaleimide and cyanate ester based sequential interpenetrating polymer networks for high temperature application

NASA Astrophysics Data System (ADS)

Geng, Xing

2005-07-01

A research area of high activity in connection with aerospace engineering has been the development of polymer thermosetting resins that can withstand temperature as high as 300°C while maintaining adequate toughness and providing ease of processing to enable low temperature and low cost composite fabrication methods. In order to meet such requirements, sequential interpenetrating polymer networks (IPNs) based on bismaleimide (BMI) and cyanate ester (CE) monomers were investigated. In these systems, a polycyanurate network is first formed in the presence of BMI and appropriate reactive diluent monomers and, in a second step, a network based on the BMI is created in the presence of a fully formed polycyanurate network. The materials developed can be processed at relatively low temperature (<150°C) and with the aid of electron beam (EB) curing. Of major importance to the success of this work was the identification of a reactive diluent that improves ease of processing and has tailored reactivity to allow for the controlled synthesis of CE-BMI sequential IPNs. Based on solubility and reactivity of a number of reactive diluents, N-acryloylmorpholine (AMP) was selected as a co-monomer for BMI copolymerization. A donor-acceptor reaction mechanism was suggested to explain the relative reactivity of a variety of reactive diluents towards maleimide functionality. The optimum processing parameters for the formation of the first network were determined through the study of metal catalyzed cure and hydrolysis of cyanate esters, whereas the reaction behavior for second network formation in terms of the influence of EB dose rate and temperature was elucidated through an in-situ kinetics study of maleimide and AMP copolymerization. Structure-property relationships were developed which allowed for the design of improved resin systems. In particular, an appropriate network coupler possessing cyanate ester and maleimide functionality was synthesized to link the polycyanurate first network to the BMI/AMP second network and thus form linked sequential IPNs (LIPNs). Consequently, Tg as high as 370°C was achieved and a fracture toughness of 120 J/m2 was obtained for resin systems that possess adequately low viscosity for processing using liquid molding techniques at low temperature.

Sulfur-based autotrophic denitrification from the micro-polluted water.

PubMed

Zhou, Weili; Liu, Xu; Dong, Xiaojing; Wang, Zheng; Yuan, Ying; Wang, Hui; He, Shengbing

2016-06-01

Eutrophication caused by high concentrations of nutrients is a huge problem for many natural lakes and reservoirs. Removing the nitrogen contamination from the low C/N water body has become an urgent need. Autotrophic denitrification with the sulfur compound as electron donor was investigated in the biofilter reactors. Through the lab-scale experiment, it was found that different sulfur compounds and different carriers caused very different treatment performances. Thiosulfate was selected to be the best electron donor and ceramsite was chosen as the suitable carrier due to the good denitrification efficiency, low cost and the good resistibility against the high hydraulic loads. Later the optimum running parameters of the process were determined. Then the pilot-scale experiment was carried out with the real micro-polluted water from the West Lake, China. The results indicated that the autotrophic denitrification with thiosulfate as electron donor was feasible and applicable for the micro-polluted lake water. Copyright © 2016. Published by Elsevier B.V.

COMPREHENSIVE CHEMICAL PROFILING OF GRAMINEOUS PLANT ROOT EXUDATES USING HIGH-RESOLUTION NMR AND MS. (R825433C007)

EPA Science Inventory

Root exudates released into soil have important functions in mobilizing metal micronutrients and for causing selective enrichment of plant beneficial soil micro-organisms that colonize the rhizosphere. Analysis of plant root exudates typically has involved chromatographic meth...

New CO2 Sensor with High Resolution and Fast Response

DTIC Science & Technology

2001-10-25

that a few solid substances selectively adsorb CO2. Combined with a Quartz Micro Balance (QMB) [1, 2] or a Surface Acoustic Wave (SAW) device [3...cardiovascular or respiratory tracts should be sterile or desinfected disposables to minimize the risk for the spread of harmful microorganisms. To

Detection of bio-signature by microscopy and mass spectrometry

NASA Astrophysics Data System (ADS)

Tulej, M.; Wiesendanger, R.; Neuland, M., B.; Meyer, S.; Wurz, P.; Neubeck, A.; Ivarsson, M.; Riedo, V.; Moreno-Garcia, P.; Riedo, A.; Knopp, G.

2017-09-01

We demonstrate detection of micro-sized fossilized bacteria by means of microscopy and mass spectrometry. The characteristic structures of lifelike forms are visualized with a micrometre spatial resolution and mass spectrometric analyses deliver elemental and isotope composition of host and fossilized materials. Our studies show that high selectivity in isolation of fossilized material from host phase can be achieved while applying a microscope visualization (location), a laser ablation ion source with sufficiently small laser spot size and applying depth profiling method. Our investigations shows that fossilized features can be well isolated from host phase. The mass spectrometric measurements can be conducted with sufficiently high accuracy and precision yielding quantitative elemental and isotope composition of micro-sized objects. The current performance of the instrument allows the measurement of the isotope fractionation in per mill level and yield exclusively definition of the origin of the investigated species by combining optical visualization of investigated samples (morphology and texture), chemical characterization of host and embedded in the host micro-sized structure. Our isotope analyses involved bio-relevant B, C, S, and Ni isotopes which could be measured with sufficiently accuracy to conclude about the nature of the micro-sized objects.

High data rate coding for the space station telemetry links.

NASA Technical Reports Server (NTRS)

Lumb, D. R.; Viterbi, A. J.

1971-01-01

Coding systems for high data rates were examined from the standpoint of potential application in space-station telemetry links. Approaches considered included convolutional codes with sequential, Viterbi, and cascaded-Viterbi decoding. It was concluded that a high-speed (40 Mbps) sequential decoding system best satisfies the requirements for the assumed growth potential and specified constraints. Trade-off studies leading to this conclusion are viewed, and some sequential (Fano) algorithm improvements are discussed, together with real-time simulation results.

mESAdb: microRNA Expression and Sequence Analysis Database

PubMed Central

Kaya, Koray D.; Karakülah, Gökhan; Yakıcıer, Cengiz M.; Acar, Aybar C.; Konu, Özlen

2011-01-01

microRNA expression and sequence analysis database (http://konulab.fen.bilkent.edu.tr/mirna/) (mESAdb) is a regularly updated database for the multivariate analysis of sequences and expression of microRNAs from multiple taxa. mESAdb is modular and has a user interface implemented in PHP and JavaScript and coupled with statistical analysis and visualization packages written for the R language. The database primarily comprises mature microRNA sequences and their target data, along with selected human, mouse and zebrafish expression data sets. mESAdb analysis modules allow (i) mining of microRNA expression data sets for subsets of microRNAs selected manually or by motif; (ii) pair-wise multivariate analysis of expression data sets within and between taxa; and (iii) association of microRNA subsets with annotation databases, HUGE Navigator, KEGG and GO. The use of existing and customized R packages facilitates future addition of data sets and analysis tools. Furthermore, the ability to upload and analyze user-specified data sets makes mESAdb an interactive and expandable analysis tool for microRNA sequence and expression data. PMID:21177657

mESAdb: microRNA expression and sequence analysis database.

PubMed

Kaya, Koray D; Karakülah, Gökhan; Yakicier, Cengiz M; Acar, Aybar C; Konu, Ozlen

2011-01-01

microRNA expression and sequence analysis database (http://konulab.fen.bilkent.edu.tr/mirna/) (mESAdb) is a regularly updated database for the multivariate analysis of sequences and expression of microRNAs from multiple taxa. mESAdb is modular and has a user interface implemented in PHP and JavaScript and coupled with statistical analysis and visualization packages written for the R language. The database primarily comprises mature microRNA sequences and their target data, along with selected human, mouse and zebrafish expression data sets. mESAdb analysis modules allow (i) mining of microRNA expression data sets for subsets of microRNAs selected manually or by motif; (ii) pair-wise multivariate analysis of expression data sets within and between taxa; and (iii) association of microRNA subsets with annotation databases, HUGE Navigator, KEGG and GO. The use of existing and customized R packages facilitates future addition of data sets and analysis tools. Furthermore, the ability to upload and analyze user-specified data sets makes mESAdb an interactive and expandable analysis tool for microRNA sequence and expression data.

Actions of arginine polyamine on voltage and ligand-activated whole cell currents recorded from cultured neurones.

PubMed Central

Scott, R. H.; Sweeney, M. I.; Kobrinsky, E. M.; Pearson, H. A.; Timms, G. H.; Pullar, I. A.; Wedley, S.; Dolphin, A. C.

1992-01-01

1. Toxins from invertebrates have proved useful tools for investigation of the properties of ion channels. In this study we describe the actions of arginine polyamine which is believed to be a close analogue of FTX, a polyamine isolated from the American funnel web spider, Agelenopsis aperta. 2. Voltage-activated Ca2+ currents and Ca(2+)-dependent Cl- currents recorded from rat cultured dorsal root ganglion neurones were reversibly inhibited by arginine polyamine (AP; 0.001 to 100 microM). Low voltage-activated T-type Ca2+ currents were significantly more sensitive to AP than high voltage-activated Ca2+ currents. The IC50 values for the actions of AP on low and high voltage-activated Ca2+ currents were 10 nM and 3 microM respectively. AP was equally effective in inhibiting high voltage-activated currents carried by Ba2+, Sr2+ or Ca2+. However, AP-induced inhibition of Ca2+ currents was attenuated by increasing the extracellular Ca2+ concentration from 2 mM to 10 mM. 3. The actions of AP on a Ca(2+)-independent K+ current were more complex, 1 microM AP enhanced this current but 10 microM AP had a dual action, initially enhancing but then inhibiting the K+ current. 4. gamma-Aminobutyric acid-activated Cl- currents were also reversibly inhibited by 1 to 10 microM AP. In contrast N-methyl-D-aspartate currents recorded from rat cultured cerebellar neurones were greatly enhanced by 10 microM AP. 5. We conclude that at a concentration of 10 nM, AP is a selective inhibitor of low threshold T-type voltage-activated Ca2+ currents.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1380382

Estimate of within population incremental selection through branch imbalance in lineage trees

PubMed Central

Liberman, Gilad; Benichou, Jennifer I.C.; Maman, Yaakov; Glanville, Jacob; Alter, Idan; Louzoun, Yoram

2016-01-01

Incremental selection within a population, defined as limited fitness changes following mutation, is an important aspect of many evolutionary processes. Strongly advantageous or deleterious mutations are detected using the synonymous to non-synonymous mutations ratio. However, there are currently no precise methods to estimate incremental selection. We here provide for the first time such a detailed method and show its precision in multiple cases of micro-evolution. The proposed method is a novel mixed lineage tree/sequence based method to detect within population selection as defined by the effect of mutations on the average number of offspring. Specifically, we propose to measure the log of the ratio between the number of leaves in lineage trees branches following synonymous and non-synonymous mutations. The method requires a high enough number of sequences, and a large enough number of independent mutations. It assumes that all mutations are independent events. It does not require of a baseline model and is practically not affected by sampling biases. We show the method's wide applicability by testing it on multiple cases of micro-evolution. We show that it can detect genes and inter-genic regions using the selection rate and detect selection pressures in viral proteins and in the immune response to pathogens. PMID:26586802

Targeting of sebaceous glands to treat acne by micro-insulated needles with radio frequency in a rabbit ear model.

PubMed

Kwon, Tae-Rin; Choi, Eun Ja; Oh, Chang Taek; Bak, Dong-Ho; Im, Song-I; Ko, Eun Jung; Hong, Hyuck Ki; Choi, Yeon Shik; Seok, Joon; Choi, Sun Young; Ahn, Gun Young; Kim, Beom Joon

2017-04-01

Many studies have investigated the application of micro-insulated needles with radio frequency (RF) to treat acne in humans; however, the use of a micro-insulated needle RF applicator has not yet been studied in an animal model. The purpose of this study was to evaluate the effectiveness of a micro-insulated needle RF applicator in a rabbit ear acne (REA) model. In this study, we investigated the effect of selectively destroying the sebaceous glands using a micro-insulated needle RF applicator on the formation of comedones induced by application of 50% oleic acid and intradermal injection of P. acnes in the orifices of the external auditory canals of rabbits. The effects of the micro-insulated needle RF applicator treatment were evaluated using regular digital photography in addition to 3D Primos imaging evaluation, Skin Visio Meter microscopic photography, and histologic analyses. Use of the micro-insulated needle RF applicator resulted in successful selective destruction of the sebaceous glands and attenuated TNF-alpha release in an REA model. The mechanisms by which micro-insulated needles with RF using 1 MHz exerts its effects may involve inhibition of comedone formation, triggering of the wound healing process, and destruction of the sebaceous glands and papules. The use of micro-insulated needles with RF applicators provides a safe and effective method for improving the appearance of symptoms in an REA model. The current in vivo study confirms that the micro-insulated needle RF applicator is selectively destroying the sebaceous glands. Lasers Surg. Med. 49:395-401, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Multiple regulation by external ATP of nifedipine-insensitive, high voltage-activated Ca(2+) current in guinea-pig mesenteric terminal arteriole.

PubMed

Morita, Hiromitsu; Sharada, Thapaliya; Takewaki, Tadashi; Ito, Yushi; Inoue, Ryuji

2002-03-15

We investigated the receptor-mediated regulation of nifedipine-insensitive, high voltage-activated Ca(2+) currents in guinea-pig terminal mesenteric arterioles (I(mVDCC)) using the whole-cell clamp technique. Screening of various vasoactive substances revealed that ATP, histamine and substance P exert modulatory effects on I(mVDCC). The effects of ATP on I(mVDCC) after complete P2X receptor desensitization exhibited a complex concentration dependence. With 5 mM Ba(2+), ATP potentiated I(mVDCC) at low concentrations (approximately 1-100 microM), but inhibited it at higher concentrations (>100 microM). The potentiating effects of ATP were abolished by suramin (100 microM) and PPADS (10 microM) and by intracellular application of GDPbetaS (500 microM), whereas a substantial part of I(mVDCC) inhibition by milimolar concentrations of ATP remained unaffected; due probably to its divalent cation chelating actions. In divalent cation-free solution, I(mVDCC) was enlarged and underwent biphasic effects by ATPgammaS and ADP, while 2-methylthio ATP (2MeSATP) exerted only inhibition, and pyrimidines such as UTP and UDP were ineffective. ATP-induced I(mVDCC) potentiation was selectively inhibited by anti-Galpha(s) antibodies or protein kinase A (PKA) inhibitory peptides and mimicked by dibutyryl cAMP. In contrast, ATP-induced inhibition was selectively inhibited by Galpha(q/11) antibodies or protein kinase C (PKC) inhibitory peptides and mimicked by PDBu. Pretreatment with pertussis toxin was ineffective. The apparent efficacy for I(mVDCC) potentiation with PKC inhibitors was: ATPgammaS > ATP>/=ADP and for inhibition with PKA inhibitors was: 2MeSATP > ATPgammaS > ATP > ADP. Neither I(mVDCC) potentiation nor inhibition showed voltage dependence. These results suggest that I(mVDCC) is multi-phasically regulated by external ATP via P2Y(11)-resembling receptor/G(s)/PKA pathway, P2Y(1)-like receptor/G(q/11)/PKC pathway, and metal chelation.

Selective serotonin reuptake inhibitors versus placebo in patients with major depressive disorder. A systematic review with meta-analysis and Trial Sequential Analysis.

PubMed

Jakobsen, Janus Christian; Katakam, Kiran Kumar; Schou, Anne; Hellmuth, Signe Gade; Stallknecht, Sandra Elkjær; Leth-Møller, Katja; Iversen, Maria; Banke, Marianne Bjørnø; Petersen, Iggiannguaq Juhl; Klingenberg, Sarah Louise; Krogh, Jesper; Ebert, Sebastian Elgaard; Timm, Anne; Lindschou, Jane; Gluud, Christian

2017-02-08

The evidence on selective serotonin reuptake inhibitors (SSRIs) for major depressive disorder is unclear. Our objective was to conduct a systematic review assessing the effects of SSRIs versus placebo, 'active' placebo, or no intervention in adult participants with major depressive disorder. We searched for eligible randomised clinical trials in The Cochrane Library's CENTRAL, PubMed, EMBASE, PsycLIT, PsycINFO, Science Citation Index Expanded, clinical trial registers of Europe and USA, websites of pharmaceutical companies, the U.S. Food and Drug Administration (FDA), and the European Medicines Agency until January 2016. All data were extracted by at least two independent investigators. We used Cochrane systematic review methodology, Trial Sequential Analysis, and calculation of Bayes factor. An eight-step procedure was followed to assess if thresholds for statistical and clinical significance were crossed. Primary outcomes were reduction of depressive symptoms, remission, and adverse events. Secondary outcomes were suicides, suicide attempts, suicide ideation, and quality of life. A total of 131 randomised placebo-controlled trials enrolling a total of 27,422 participants were included. None of the trials used 'active' placebo or no intervention as control intervention. All trials had high risk of bias. SSRIs significantly reduced the Hamilton Depression Rating Scale (HDRS) at end of treatment (mean difference -1.94 HDRS points; 95% CI -2.50 to -1.37; P < 0.00001; 49 trials; Trial Sequential Analysis-adjusted CI -2.70 to -1.18); Bayes factor below predefined threshold (2.01*10 -23 ). The effect estimate, however, was below our predefined threshold for clinical significance of 3 HDRS points. SSRIs significantly decreased the risk of no remission (RR 0.88; 95% CI 0.84 to 0.91; P < 0.00001; 34 trials; Trial Sequential Analysis adjusted CI 0.83 to 0.92); Bayes factor (1426.81) did not confirm the effect). SSRIs significantly increased the risks of serious adverse events (OR 1.37; 95% CI 1.08 to 1.75; P = 0.009; 44 trials; Trial Sequential Analysis-adjusted CI 1.03 to 1.89). This corresponds to 31/1000 SSRI participants will experience a serious adverse event compared with 22/1000 control participants. SSRIs also significantly increased the number of non-serious adverse events. There were almost no data on suicidal behaviour, quality of life, and long-term effects. SSRIs might have statistically significant effects on depressive symptoms, but all trials were at high risk of bias and the clinical significance seems questionable. SSRIs significantly increase the risk of both serious and non-serious adverse events. The potential small beneficial effects seem to be outweighed by harmful effects. PROSPERO CRD42013004420.

Coaxial charged particle energy analyzer

NASA Technical Reports Server (NTRS)

Kelly, Michael A. (Inventor); Bryson, III, Charles E. (Inventor); Wu, Warren (Inventor)

2011-01-01

A non-dispersive electrostatic energy analyzer for electrons and other charged particles having a generally coaxial structure of a sequentially arranged sections of an electrostatic lens to focus the beam through an iris and preferably including an ellipsoidally shaped input grid for collimating a wide acceptance beam from a charged-particle source, an electrostatic high-pass filter including a planar exit grid, and an electrostatic low-pass filter. The low-pass filter is configured to reflect low-energy particles back towards a charged particle detector located within the low-pass filter. Each section comprises multiple tubular or conical electrodes arranged about the central axis. The voltages on the lens are scanned to place a selected energy band of the accepted beam at a selected energy at the iris. Voltages on the high-pass and low-pass filters remain substantially fixed during the scan.

EDITORIAL: Special issue for papers selected from The 8th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2008) Special issue for papers selected from The 8th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2008)

NASA Astrophysics Data System (ADS)

Tanaka, Shuji

2009-09-01

This special issue of the Journal of Micromechanics and Microengineering features papers selected from The 8th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2008) with the 2nd Symposium on Micro Environmental Machine Systems (μMEMS 2008). The workshop was held in Sendai, Japan on 9-12 November 2008 by Tohoku University. This is the second time that the PowerMEMS workshop has been held in Sendai, following the first workshop in 2000. Power MEMS is one of the newest categories of MEMS, which encompasses microdevices and microsystems for power generation, energy conversion and propulsion. The first concept of Power MEMS was born in the late 1990's from a MEMS-based gas turbine project at Massachusetts Institute of Technology. After that, the research and development of Power MEMS have been promoted by the strong need for compact power sources with high energy and/or power density. Since its inception, Power MEMS has expanded to include not only various MEMS-based power generators but also small energy machines and microdevices for macro power generators. Previously, the main topics of the PowerMEMS workshop were miniaturized gas turbines and micro fuel cells, but recently, energy harvesting has been the hottest topic. In 2008, energy harvesting had a 41% share in the 118 accepted regular papers. This special issue includes 19 papers on various topics. Finally, I would like to express my sincere appreciation to the members of the International Steering Committee, the Technical Program Committee, the Local Organizing Committee and financial supporters. This special issue was edited in collaboration with the staff of IOP Publishing.

Carbon molecular sieve based micro-matrix-solid-phase dispersion for the extraction of polyphenols in pomegranate peel by UHPLC-Q-TOF/MS.

PubMed

Du, Li-Jing; Huang, Jian-Ping; Wang, Bin; Wang, Chen-Hui; Wang, Qiu-Yan; Hu, Yu-Han; Yi, Ling; Cao, Jun; Peng, Li-Qing; Chen, Yu-Bo; Zhang, Qi-Dong

2018-06-04

A rapid, simple and efficient sample extraction method based on micro-matrix-solid-phase dispersion (micro-MSPD) was applied to the extraction of polyphenols from pomegranate peel. Five target analytes were determined by ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry. Carbon molecular sieve (CMS) was firstly used as dispersant to improve extraction efficiency in micro-MSPD. The major micro-MSPD parameters, such as type of dispersant, amount of dispersant, grinding time and the type and the volume of elution solvents, were studied and optimized. Under optimized conditions, 26 mg of pomegranate peel was dispersed with 32.5 mg of CMS, the grinding time was selected as 90 s, the dispersed sample was eluted with 100 μL of methanol. Results showed that the proposed method was of good linearity for concentrations of analytes against their peak areas (coefficient of determination r 2 >0.990), the limit of the detection was as low as 3.2 ng/mL, and the spiking recoveries were between 88.1% and 106%. Satisfactory results were obtained for the extraction of gallic acid, punicalagin A, punicalagin B, catechin and ellagic acid from pomegranate peel sample, which demonstrated nice reliability and high sensitivity of this approach. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Collaborative Filtering Based on Sequential Extraction of User-Item Clusters

NASA Astrophysics Data System (ADS)

Honda, Katsuhiro; Notsu, Akira; Ichihashi, Hidetomo

Collaborative filtering is a computational realization of “word-of-mouth” in network community, in which the items prefered by “neighbors” are recommended. This paper proposes a new item-selection model for extracting user-item clusters from rectangular relation matrices, in which mutual relations between users and items are denoted in an alternative process of “liking or not”. A technique for sequential co-cluster extraction from rectangular relational data is given by combining the structural balancing-based user-item clustering method with sequential fuzzy cluster extraction appraoch. Then, the tecunique is applied to the collaborative filtering problem, in which some items may be shared by several user clusters.

Discussion on the solar concentrating thermoelectric generation using micro-channel heat pipe array

NASA Astrophysics Data System (ADS)

Li, Guiqiang; Feng, Wei; Jin, Yi; Chen, Xiao; Ji, Jie

2017-11-01

Heat pipe is a high efficient tool in solar energy applications. In this paper, a novel solar concentrating thermoelectric generation using micro-channel heat pipe array (STEG-MCHP) was presented. The flat-plate micro-channel heat pipe array not only has a higher heat transfer performance than the common heat pipe, but also can be placed on the surface of TEG closely, which can further reduce the thermal resistance between the heat pipe and the TEG. A preliminary comparison experiment was also conducted to indicate the advantages of the STEG-MCHP. The optimization based on the model verified by the experiment was demonstrated, and the concentration ratio and selective absorbing coating area were also discussed. In addition, the cost analysis was also performed to compare between the STEG-MCHP and the common solar concentrating TEGs in series. The outcome showed that the solar concentrating thermoelectric generation using micro-channel heat pipe array has the higher electrical efficiency and lower cost, which may provide a suitable way for solar TEG applications.

[Co-composting high moisture vegetable waste and flower waste in a sequential fed operation].

PubMed

Zhang, Xiangfeng; Wang, Hongtao; Nie, Yongfeng

2003-11-01

Co-composting of high moisture vegetable wastes (celery and cabbage) and flower wastes (carnation) were studied in a sequential fed bed. The preliminary materials of composting were celery and carnation wastes. The sequential fed materials of composting were cabbage wastes and were fed every 4 days. Moisture content of mixture materials was between 60% and 70%. Composting was done in an aerobic static bed of composting based temperature feedback and control via aeration rate regulation. Aeration was ended when temperature of the pile was about 40 degrees C. Changes of composting of temperature, aeration rate, water content, organic matter, ash, pH, volume, NH4(+)-N, and NO3(-)-N were studied. Results show that co-composting of high moisture vegetable wastes and flower wastes, in a sequential fed aerobic static bed based temperature feedback and control via aeration rate regulation, can stabilize organic matter and removal water rapidly. The sequential fed operation are effective to overcome the difficult which traditional composting cannot applied successfully where high moisture vegetable wastes in more excess of flower wastes, such as Dianchi coastal.

Sequential and Mixed Genetic Algorithm and Learning Automata (SGALA, MGALA) for Feature Selection in QSAR

PubMed Central

MotieGhader, Habib; Gharaghani, Sajjad; Masoudi-Sobhanzadeh, Yosef; Masoudi-Nejad, Ali

2017-01-01

Feature selection is of great importance in Quantitative Structure-Activity Relationship (QSAR) analysis. This problem has been solved using some meta-heuristic algorithms such as GA, PSO, ACO and so on. In this work two novel hybrid meta-heuristic algorithms i.e. Sequential GA and LA (SGALA) and Mixed GA and LA (MGALA), which are based on Genetic algorithm and learning automata for QSAR feature selection are proposed. SGALA algorithm uses advantages of Genetic algorithm and Learning Automata sequentially and the MGALA algorithm uses advantages of Genetic Algorithm and Learning Automata simultaneously. We applied our proposed algorithms to select the minimum possible number of features from three different datasets and also we observed that the MGALA and SGALA algorithms had the best outcome independently and in average compared to other feature selection algorithms. Through comparison of our proposed algorithms, we deduced that the rate of convergence to optimal result in MGALA and SGALA algorithms were better than the rate of GA, ACO, PSO and LA algorithms. In the end, the results of GA, ACO, PSO, LA, SGALA, and MGALA algorithms were applied as the input of LS-SVR model and the results from LS-SVR models showed that the LS-SVR model had more predictive ability with the input from SGALA and MGALA algorithms than the input from all other mentioned algorithms. Therefore, the results have corroborated that not only is the predictive efficiency of proposed algorithms better, but their rate of convergence is also superior to the all other mentioned algorithms. PMID:28979308

Sequential and Mixed Genetic Algorithm and Learning Automata (SGALA, MGALA) for Feature Selection in QSAR.

PubMed

MotieGhader, Habib; Gharaghani, Sajjad; Masoudi-Sobhanzadeh, Yosef; Masoudi-Nejad, Ali

2017-01-01

Feature selection is of great importance in Quantitative Structure-Activity Relationship (QSAR) analysis. This problem has been solved using some meta-heuristic algorithms such as GA, PSO, ACO and so on. In this work two novel hybrid meta-heuristic algorithms i.e. Sequential GA and LA (SGALA) and Mixed GA and LA (MGALA), which are based on Genetic algorithm and learning automata for QSAR feature selection are proposed. SGALA algorithm uses advantages of Genetic algorithm and Learning Automata sequentially and the MGALA algorithm uses advantages of Genetic Algorithm and Learning Automata simultaneously. We applied our proposed algorithms to select the minimum possible number of features from three different datasets and also we observed that the MGALA and SGALA algorithms had the best outcome independently and in average compared to other feature selection algorithms. Through comparison of our proposed algorithms, we deduced that the rate of convergence to optimal result in MGALA and SGALA algorithms were better than the rate of GA, ACO, PSO and LA algorithms. In the end, the results of GA, ACO, PSO, LA, SGALA, and MGALA algorithms were applied as the input of LS-SVR model and the results from LS-SVR models showed that the LS-SVR model had more predictive ability with the input from SGALA and MGALA algorithms than the input from all other mentioned algorithms. Therefore, the results have corroborated that not only is the predictive efficiency of proposed algorithms better, but their rate of convergence is also superior to the all other mentioned algorithms.

Bacteremic complications of intravascular catheter tip colonization with Gram-negative micro-organisms in patients without preceding bacteremia.

PubMed

van Eck van der Sluijs, A; Oosterheert, J J; Ekkelenkamp, M B; Hoepelman, I M; Peters, Edgar J G

2012-06-01

Although Gram-negative micro-organisms are frequently associated with catheter-related bloodstream infections, the prognostic value and clinical implication of a positive catheter tip culture with Gram-negative micro-organisms without preceding bacteremia remains unclear. We determined the outcomes of patients with intravascular catheters colonized with these micro-organisms, without preceding positive blood cultures, and identified risk factors for the development of subsequent Gram-negative bacteremia. All patients with positive intravascular catheter tip cultures with Gram-negative micro-organisms at the University Medical Center, Utrecht, The Netherlands, between 2005 and 2009, were retrospectively studied. Patients with Gram-negative bacteremia within 48 h before catheter removal were excluded. The main outcome measure was bacteremia with Gram-negative micro-organisms. Other endpoints were length of the hospital stay, in-hospital mortality, secondary complications of Gram-negative bacteremia, and duration of intensive care admission. A total of 280 catheters from 248 patients were colonized with Gram-negative micro-organisms. Sixty-seven cases were excluded because of preceding positive blood cultures, leaving 213 catheter tips from 181 patients for analysis. In 40 (19%) cases, subsequent Gram-negative bacteremia developed. In multivariate analysis, arterial catheters were independently associated with subsequent Gram-negative bacteremia (odds ratio [OR] = 5.00, 95% confidence interval [CI]: 1.20-20.92), as was selective decontamination of the digestive tract (SDD) (OR = 2.47, 95% CI: 1.07-5.69). Gram-negative bacteremia in patients who received SDD was predominantly caused by cefotaxime (part of the SDD)-resistant organisms. Mortality was significantly higher in the group with subsequent Gram-negative bacteremia (35% versus 20%, OR = 2.12, 95% CI: 1.00-4.49). Patients with a catheter tip colonized with Gram-negative micro-organisms had a high chance of subsequent Gram-negative bacteremia from any cause. This may be clinically relevant, as starting antibiotic treatment pre-emptively in high-risk patients with Gram-negative micro-organisms cultured from arterial intravenous catheters may be beneficial.

Changes in zinc speciation with mine tailings acidification in a semi-arid weathering environment

PubMed Central

Hayes, Sarah M.; O’Day, Peggy A.; Webb, Sam M.; Maier, Raina M.; Chorover, Jon

2011-01-01

High concentrations of residual metal contaminants in mine tailings can be transported easily by wind and water, particularly when tailings remain unvegetated for decades following mining cessation, as is the case in semi-arid landscapes. Understanding the speciation and mobility of contaminant metal(loid)s, particularly in surficial tailings, is essential to controlling their phytotoxicities and to revegetating impacted sites. In prior work, we showed that surficial tailings samples from the Klondyke State Superfund Site (AZ, USA), ranging in pH from 5.4 to 2.6, represent a weathering series, with acidification resulting from sulfide mineral oxidation, long-term Fe hydrolysis, and a concurrent decrease in total (6,000 to 450 mg kg−1) and plant-available (590 to 75 mg kg−1) Zn due to leaching losses and changes in Zn speciation. Here, we used bulk and micro-focused Zn K-edge X-ray absorption spectroscopy (XAS) data and a six-step sequential extraction procedure to determine tailings solid phase Zn speciation. Bulk sample spectra were fit by linear combination using three references: Zn-rich phyllosilicate (Zn0.8talc), Zn sorbed to ferrihydrite (ZnadsFeOx), and zinc sulfate (ZnSO4·7H2O). Analyses indicate that Zn sorbed in tetrahedral coordination to poorly-crystalline Fe and Mn (oxyhydr)oxides decreases with acidification in the weathering sequence, whereas octahedral zinc in sulfate minerals and crystalline Fe oxides undergoes a relative accumulation. Micro-scale analyses identified hetaerolite (ZnMn2O4), hemimorphite (Zn4Si2O7(OH)2·H2O) and sphalerite (ZnS) as minor phases. Bulk and micro-focused spectroscopy complement the chemical extraction results and highlight the importance of using a multi-method approach to interrogate complex tailings systems. PMID:21761897

Characterization of a recombinant type II 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase from Helicobacter pylori.

PubMed

Webby, Celia J; Patchett, Mark L; Parker, Emily J

2005-08-15

DAH7P (3-Deoxy-D-arabino-heptulosonate 7-phosphate) synthase catalyses the condensation reaction between phosphoenolpyruvate (PEP) and D-erythrose 4-phosphate (E4P) as the first committed step in the biosynthesis of aromatic compounds in plants and micro-organisms. Previous work has identified two families of DAH7P synthases based on sequence similarity and molecular mass, with the majority of the mechanistic and structural studies being carried out on the type I paralogues from Escherichia coli. Whereas a number of organisms possess genes encoding both type I and type II DAH7P synthases, the pathogen Helicobacter pylori has only a single, type II, enzyme. Recombinant DAH7P synthase from H. pylori was partially solubilized by co-expression with chaperonins GroEL/GroES in E. coli, and purified to homogeneity. The enzyme reaction follows an ordered sequential mechanism with the following kinetic parameters: K(m) (PEP), 3 microM; K(m) (E4P), 6 microM; and kcat, 3.3 s(-1). The enzyme reaction involves interaction of the si face of PEP with the re face of E4P. H. pylori DAH7P synthase is not inhibited by phenylalanine, tyrosine, tryptophan or chorismate. EDTA inactivates the enzyme, and activity is restored by a range of bivalent metal ions, including (in order of decreasing effectiveness) Co2+, Mn2+, Ca2+, Mg2+, Cu2+ and Zn2+. Analysis of type II DAH7P synthase sequences reveals several highly conserved motifs, and comparison with the type I enzymes suggests that catalysis by these two enzyme types occurs on a similar active-site scaffold and that the two DAH7P synthase families may indeed be distantly related.

LC-lens array with light field algorithm for 3D biomedical applications

NASA Astrophysics Data System (ADS)

Huang, Yi-Pai; Hsieh, Po-Yuan; Hassanfiroozi, Amir; Martinez, Manuel; Javidi, Bahram; Chu, Chao-Yu; Hsuan, Yun; Chu, Wen-Chun

2016-03-01

In this paper, liquid crystal lens (LC-lens) array was utilized in 3D bio-medical applications including 3D endoscope and light field microscope. Comparing with conventional plastic lens array, which was usually placed in 3D endoscope or light field microscope system to record image disparity, our LC-lens array has higher flexibility of electrically changing its focal length. By using LC-lens array, the working distance and image quality of 3D endoscope and microscope could be enhanced. Furthermore, the 2D/3D switching ability could be achieved if we turn off/on the electrical power on LClens array. In 3D endoscope case, a hexagonal micro LC-lens array with 350um diameter was placed at the front end of a 1mm diameter endoscope. With applying electric field on LC-lens array, the 3D specimen would be recorded as from seven micro-cameras with different disparity. We could calculate 3D construction of specimen with those micro images. In the other hand, if we turn off the electric field on LC-lens array, the conventional high resolution 2D endoscope image would be recorded. In light field microscope case, the LC-lens array was placed in front of the CMOS sensor. The main purpose of LC-lens array is to extend the refocusing distance of light field microscope, which is usually very narrow in focused light field microscope system, by montaging many light field images sequentially focusing on different depth. With adjusting focal length of LC-lens array from 2.4mm to 2.9mm, the refocusing distance was extended from 1mm to 11.3mm. Moreover, we could use a LC wedge to electrically shift the optics axis and increase the resolution of light field.

Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size determination

NASA Astrophysics Data System (ADS)

Koziel, Slawomir; Bekasiewicz, Adrian

2018-02-01

In this article, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement for yielding the optimal designs at the high-fidelity electromagnetic (EM) simulation model level. For the sake of computational efficiency, the first step is realized at the level of a low-fidelity (coarse-discretization) EM model by sequential construction and relocation of small design space segments (patches) in order to create a path connecting the extreme Pareto front designs obtained beforehand. The second stage involves response correction techniques and local response surface approximation models constructed by reusing EM simulation data acquired in the first step. A major contribution of this work is an automated procedure for determining the patch dimensions. It allows for appropriate selection of the number of patches for each geometry variable so as to ensure reliability of the optimization process while maintaining its low cost. The importance of this procedure is demonstrated by comparing it with uniform patch dimensions.

Long-term biological hydrogen production by agar immobilized Rhodobacter capsulatus in a sequential batch photobioreactor.

PubMed

Elkahlout, Kamal; Alipour, Siamak; Eroglu, Inci; Gunduz, Ufuk; Yucel, Meral

2017-04-01

In this study, agar immobilization technique was employed for biological hydrogen production using Rhodobacter capsulatus DSM 1710 (wild type) and YO3 (hup-mutant) strains in sequential batch process. Different agar and glutamate concentrations were tested with defined nutrient medium. Agar concentration 4% (w/v) and 4 mM glutamate were selected for bacterial immobilization in terms of rate and longevity of hydrogen production. Acetate concentration was increased from 40 to 60-100 and 60 mM gave best results with both bacterial strains immobilized in 4% (w/v) agar. Cell concentration was increased from 2.5 to 5 mg dcw mL -1 agar and it was found that increasing cell concentration of wild-type strain caused decrease in yield and productivity while these parameters improved by increasing cell concentration of mutant strain. Also, the hydrogen production time has extended from 17 days up to 60 days according to the process conditions and parameters. Hydrogen production by immobilized photosynthetic bacteria is a convenient technology for hydrogen production as it enables to produce hydrogen with high organic acid concentrations comparing to suspended cultures. Besides, immobilization increases the stability of the system and allowed sequential batch operation for long-term application.

Actions of arginine polyamine on voltage and ligand-activated whole cell currents recorded from cultured neurones.

PubMed

Scott, R H; Sweeney, M I; Kobrinsky, E M; Pearson, H A; Timms, G H; Pullar, I A; Wedley, S; Dolphin, A C

1992-05-01

1. Toxins from invertebrates have proved useful tools for investigation of the properties of ion channels. In this study we describe the actions of arginine polyamine which is believed to be a close analogue of FTX, a polyamine isolated from the American funnel web spider, Agelenopsis aperta. 2. Voltage-activated Ca2+ currents and Ca(2+)-dependent Cl- currents recorded from rat cultured dorsal root ganglion neurones were reversibly inhibited by arginine polyamine (AP; 0.001 to 100 microM). Low voltage-activated T-type Ca2+ currents were significantly more sensitive to AP than high voltage-activated Ca2+ currents. The IC50 values for the actions of AP on low and high voltage-activated Ca2+ currents were 10 nM and 3 microM respectively. AP was equally effective in inhibiting high voltage-activated currents carried by Ba2+, Sr2+ or Ca2+. However, AP-induced inhibition of Ca2+ currents was attenuated by increasing the extracellular Ca2+ concentration from 2 mM to 10 mM. 3. The actions of AP on a Ca(2+)-independent K+ current were more complex, 1 microM AP enhanced this current but 10 microM AP had a dual action, initially enhancing but then inhibiting the K+ current. 4. gamma-Aminobutyric acid-activated Cl- currents were also reversibly inhibited by 1 to 10 microM AP. In contrast N-methyl-D-aspartate currents recorded from rat cultured cerebellar neurones were greatly enhanced by 10 microM AP. 5. We conclude that at a concentration of 10 nM, AP is a selective inhibitor of low threshold T-type voltage-activated Ca2+ currents. However, at higher concentrations 1-10 microM AP interacts with ion channels or other membrane constituents to produce a variety of actions on both voltage and ligand gated ion channels.

Activated Biomass-derived Graphene-based Carbons for Supercapacitors with High Energy and Power Density.

PubMed

Jung, SungHoon; Myung, Yusik; Kim, Bit Na; Kim, In Gyoo; You, In-Kyu; Kim, TaeYoung

2018-01-30

Here, we present a facile and low-cost method to produce hierarchically porous graphene-based carbons from a biomass source. Three-dimensional (3D) graphene-based carbons were produced through continuous sequential steps such as the formation and transformation of glucose-based polymers into 3D foam-like structures and their subsequent carbonization to form the corresponding macroporous carbons with thin graphene-based carbon walls of macropores and intersectional carbon skeletons. Physical and chemical activation was then performed on this carbon to create micro- and meso-pores, thereby producing hierarchically porous biomass-derived graphene-based carbons with a high Brunauer-Emmett-Teller specific surface area of 3,657 m 2  g -1 . Owing to its exceptionally high surface area, interconnected hierarchical pore networks, and a high degree of graphitization, this carbon exhibited a high specific capacitance of 175 F g -1 in ionic liquid electrolyte. A supercapacitor constructed with this carbon yielded a maximum energy density of 74 Wh kg -1 and a maximum power density of 408 kW kg -1 , based on the total mass of electrodes, which is comparable to those of the state-of-the-art graphene-based carbons. This approach holds promise for the low-cost and readily scalable production of high performance electrode materials for supercapacitors.

Professional Orchestral Conductors' Use of Selected Teaching Behaviors in Rehearsal

ERIC Educational Resources Information Center

Whitaker, Jennifer A.

2017-01-01

This descriptive study examined professional conductors' use of rehearsal time in sequential pattern components, discussing task presentation targets, and using verbal imagery and modeling techniques. Commercially available videos of 15 professional conductors rehearsing prominent orchestras were scripted, coded, and timed for selected teaching…

Psychological Principles in Materials Selection.

ERIC Educational Resources Information Center

Colvin, Cynthia M.

Those psychological principles which might aid the teacher in the selection of instructional materials are examined. Since learning is a process which builds sequentially on past learning, beginning reading materials should include words that have personal relevance for the individual child. Meaningful material is learned more quickly than…

Tachykinins mediate contraction of the human lower esophageal sphincter in vitro via activation of NK2 receptors.

PubMed

Huber, O; Bertrand, C; Bunnett, N W; Pellegrini, C A; Nadel, J A; Nakazato, P; Debas, H T; Geppetti, P

1993-08-03

The contractile response to natural tachykinins and selective peptide agonists for tachykinin receptors was studied in strips of circular smooth muscle of human lower esophageal sphincter in vitro. The effects of phosphoramidon, which inhibits neutral endopeptidase (EC.3.4.24.11) and of the non-peptide compounds, SR 48968 and CP-96,345, which selectively block NK1 and NK2 receptors, respectively, were also investigated. Substance P, neurokinin A and neurokinin B produced a concentration-dependent contractile response. The rank order of potency was neurokinin A > neurokinin B > substance P. Phosphoramidon (1 microM) potentiated the response to substance P without changing the order of potency of natural tachykinins. The NK2-selective agonist, ([ beta Ala8]neurokinin A-(4-10)), produced a concentration-dependent contraction. The NK1 ([Sar9,Met(O2)11]substance P, 1 microM) and NK3 ([MePhe7]neurokinin B, 1 microM) selective agonists, however, did not exert any contractile effect. The selective NK2 antagonist, SR 48968, potently inhibited in a concentration-dependent (10 nM-1 microM) manner the response to neurokinin A, without affecting the response to carbachol. The selective NK1 antagonist, CP-96,345 (1 microM), did not affect the response to neurokinin A. These results indicate that tachykinins contract the circular muscle of human lower esophageal sphincter, and that this effect is mediated by NK2 receptor stimulation. Moreover, a phosphoramidon-sensitive mechanism plays a role in the regulation of the response to substance P.

Synthesis of Renewable Lubricant Alkanes from Biomass-Derived Platform Chemicals.

PubMed

Gu, Mengyuan; Xia, Qineng; Liu, Xiaohui; Guo, Yong; Wang, Yanqin

2017-10-23

The catalytic synthesis of liquid alkanes from renewable biomass has received tremendous attention in recent years. However, bio-based platform chemicals have not to date been exploited for the synthesis of highly branched lubricant alkanes, which are currently produced by hydrocracking and hydroisomerization of long-chain n-paraffins. A selective catalytic synthetic route has been developed for the production of highly branched C 23 alkanes as lubricant base oil components from biomass-derived furfural and acetone through a sequential four-step process, including aldol condensation of furfural with acetone to produce a C 13 double adduct, selective hydrogenation of the adduct to a C 13 ketone, followed by a second condensation of the C 13 ketone with furfural to generate a C 23 aldol adduct, and finally hydrodeoxygenation to give highly branched C 23 alkanes in 50.6 % overall yield from furfural. This work opens a general strategy for the synthesis of high-quality lubricant alkanes from renewable biomass. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exploiting microRNA Specificity and Selectivity: Paving a Sustainable Path Towards Precision Medicine.

PubMed

Santulli, Gaetano

2015-01-01

In his State of the Union address before both chambers of the US Congress, President Barack Obama called for increased investment in US infrastructure and research and announced the launch of a new Precision Medicine Initiative, aiming to accelerate biomedical discovery. Due to their well-established selectivity and specificity, microRNAs can represent a useful tool, both in diagnosis and therapy, in forging the path towards the achievement of precision medicine. This introductory chapter represents a guide for the Reader in examining the functional roles of microRNAs in the most diverse aspects of clinical practice, which will be explored in this third volume of the microRNA trilogy.

Exploiting microRNA Specificity and Selectivity: Paving a Sustainable Path Towards Precision Medicine

PubMed Central

2016-01-01

In his State of the Union address before both chambers of the US Congress, President Barack Obama called for increased investment in US infrastructure and research and announced the launch of a new Precision Medicine Initiative, aiming to accelerate biomedical discovery. Due to their well-established selectivity and specificity, microRNAs can represent a useful tool, both in diagnosis and therapy, in forging the path towards the achievement of precision medicine. This introductory chapter represents a guide for the Reader in examining the functional roles of microRNAs in the most diverse aspects of clinical practice, which will be explored in this third volume of the microRNA trilogy. PMID:26663175

The insulin-like growth factor-1 receptor inhibitor PPP produces only very limited resistance in tumor cells exposed to long-term selection.

PubMed

Vasilcanu, D; Weng, W-H; Girnita, A; Lui, W-O; Vasilcanu, R; Axelson, M; Larsson, O; Larsson, C; Girnita, L

2006-05-25

The cyclolignan PPP was recently demonstrated to inhibit the activity of insulin-like growth factor-1 receptor (IGF-1R), without affecting the highly homologous insulin receptor. In addition, PPP caused complete regression of xenografts derived from various types of cancer. These data highlight the use of this compound in cancer treatment. However, a general concern with antitumor agents is development of resistance. In light of this problem, we aimed to investigate whether malignant cells may develop serious resistance to PPP. After trying to select 10 malignant cell lines, with documented IGF-1R expression and apoptotic responsiveness to PPP treatment (IC50s less than 0.1 microM), only two survived an 80-week selection but could only tolerate maximal PPP doses of 0.2 and 0.5 microM, respectively. Any further increase in the PPP dose resulted in massive cell death. These two cell lines were demonstrated not to acquire any essential alteration in responsiveness to PPP regarding IGF-1-induced IGF-1R phosphorylation. Neither did they exhibit any increase in expression of the multidrug resistance proteins MDR1 or MRP1. Consistently, they did not exhibit decreased sensitivity to conventional cytostatic drugs. Rather, the sensitivity was increased. During the first half of the selection period, both cell lines responded with a temporary and moderate increase in IGF-1R expression, which appeared to be because of an increased transcription of the IGF-1R gene. This increase in IGF-1R might be necessary to make cells competent for further selection but only up to a PPP concentration of 0.2 and 0.5 microM. In conclusion, malignant cells develop no or remarkably weak resistance to the IGF-1R inhibitor PPP.

Tachykinin antagonists and capsaicin-induced contraction of the rat isolated urinary bladder: evidence for tachykinin-mediated cotransmission.

PubMed Central

Maggi, C. A.; Patacchini, R.; Santicioli, P.; Giuliani, S.

1991-01-01

1. The possible involvement of tachykinins (TKs) in the contraction produced by capsaicin in the rat isolated urinary bladder was addressed on the hypothesis that co-release of substance P (SP) and neurokinin A (NKA) occurs from sensory nerve terminals. 2. A low concentration of SP (30 nM) produced a rapid contraction which faded to baseline within 10 min. A low concentration of NKA (10 nM) produced a slowly developing contraction which was still evident at 10 min. Capsaicin (1 microM) produced a rapid phasic response and a tonic response (late response to capsaicin). Co-administration of SP and NKA mimicked the response to capsaicin more than each TK alone. 3. Fading of the response to SP was not caused by receptor desensitization and was partially prevented by peptidase inhibitors. 4. Spantide (3 microM) selectively antagonized the SP-induced contraction while L-659,877 (3-10 microM) or MEN 10,376 (10-30 microM) which are NK2 receptor selective antagonists selectively blocked the response to NKA. Co-administration of spantide and L-659,877 inhibited the response to both SP and NKA by an amount not greater than that produced by each antagonist alone. 5. Spantide selectively reduced the peak response to capsaicin, while leaving the late response unaffected. L-659,877 (3 microM) and MEN 10,376 (10 microM) selectively inhibited the late response to capsaicin while, at higher concentrations, also reduced the peak response to capsaicin. Co-administration of spantide and L-659,877 reduced the peak response to capsaicin more than that produced by each antagonist alone. 6. Bombesin (10 nM) produced a tonic contraction similar to that induced by NKA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1715797

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers

DOEpatents

Evans, R.J.; Chum, H.L.

1994-06-14

A process is described using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents. 68 figs.

Controlled catalystic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents.

Hemicellulose block copolymers made from woods for wide-range directed self-assembly lithography enabling wider range of applicable patterning size

NASA Astrophysics Data System (ADS)

Morita, Kazuyo; Yamamoto, Kimiko

2017-03-01

Xylan, one of hemicellulose family, block copolymer was newly developed for wide-range directed self-assembly lithography (DSA). Xylan is higher hydrophilic material because of having many hydroxy groups in one molecule. It means that xylan block copolymer has a possibility of high-chi block copolymer. Generally, DSA is focused on microphase separation for smaller size with high-chi block copolymer and not well known for larger size. In this study, xylan block copolymer was confirmed enabling wider range of patterning size, from smaller size to larger size. The key of xylan block copolymer is a new molecular structure of block copolymer and sugar chain control technology. Sugar content is the important parameter for not only micro-phase separation property but also line edge roughness (LER) and defects. Based on the sugar control technology, wide-range (hp 8.3nm to 26nm L/S and CD 10nm to 51nm hole) DSA patterning was demonstrated. Additionally it was confirmed that xylan block copolymer is suitable for sequential infiltration synthesis (SIS) process.

Superhydrophobic hybrid inorganic-organic thiol-ene surfaces fabricated via spray-deposition and photopolymerization.

PubMed

Sparks, Bradley J; Hoff, Ethan F T; Xiong, Li; Goetz, James T; Patton, Derek L

2013-03-13

We report a simple and versatile method for the fabrication of superhydrophobic inorganic-organic thiol-ene coatings via sequential spray-deposition and photopolymerization under ambient conditions. The coatings are obtained by spray-deposition of UV-curable hybrid inorganic-organic thiol-ene resins consisting of pentaerythritol tetra(3-mercaptopropionate) (PETMP), triallyl isocyanurate (TTT), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (TMTVSi), and hydrophobic fumed silica nanoparticles. The spray-deposition process and nanoparticle agglomeration/dispersion provide surfaces with hierarchical morphologies exhibiting both micro- and nanoscale roughness. The wetting behavior, dependent on the concentration of TMTVSi and hydrophobic silica nanoparticles, can be varied over a broad range to ultimately provide coatings with high static water contact angles (>150°), low contact angle hysteresis, and low roll off angles (<5°). The cross-linked thiol-ene coatings are solvent resistant, stable at low and high pH, and maintain superhydrophobic wetting behavior after extended exposure to elevated temperatures. We demonstrate the versatility of the spray-deposition and UV-cure process on a variety of substrate surfaces including glass, paper, stone, and cotton fabric.

Combinatorial synthesis and hydrogenation of Mg/Al libraries prepared by electron beam physical vapor deposition.

PubMed

Garcia, Gemma; Doménech-Ferrer, Roger; Pi, Francesc; Santiso, Josep; Rodríguez-Viejo, Javier

2007-01-01

We have grown thin film libraries of the Mg-Al system using a high-throughput synthesis methodology that combines the sequential deposition of pure elements (Mg and Al) by an electron-beam (e-beam) evaporation technique and the use of a special set of moving shadow masks. This novel mask has been designed to simultaneously prepare four identical arrays of different compositions that will permit the characterization of the same library after several treatments. Wavelength dispersive spectroscopy (WDS) and micro-X-ray diffraction have been used as high-throughput screening techniques for the determination of the composition and structure of every member of the library in the as-deposited state and after hydrogenation at 1 atm of H2 during 24 h at three different temperatures: 60, 80, and 110 degrees C. We have analyzed the influence of the Mg-Al ratio on the hydrogenation of magnesium, as well as on the appearance of complex hydride phases. We have also found that aluminum can act as a catalyzer for the hydrogenation reaction of magnesium.

High-performance liquid chromatography-mass spectrometry-based acetylcholinesterase assay for the screening of inhibitors in natural extracts.

PubMed

de Jong, Camiel F; Derks, Rico J E; Bruyneel, Ben; Niessen, Wilfried; Irth, Hubertus

2006-04-21

The present paper describes a High-performance liquid chromatography-mass spectrometry (LC-MS) methodology for the screening of acetylcholinesterase (AChE) inhibitors in natural extracts. AChE activity of sample components is monitored by a post-column biochemical assay that is based on the separate, sequential mixing of AChE and acetylcholine, respectively, with the HPLC eluate. AChE inhibitors are detected by measuring a decrease of product formation using electrospray MS. Ammonium bicarbonate was used as buffer in order to achieve optimum compatibility between biochemical assay and MS detection conditions. The assay is robust and stable for over 13 h and compares favourably with other AChE assays in terms of stability and sensitivity. IC(50) values of 9-aminoacridine, galanthamine, gallamine, (-)-huperzine A and thioflavin T were determined to be 0.12, 0.38, 6.4, 0.46 and 3.2 microM, respectively. The assay was used to effectively identify an AChE inhibitor present in a crude extract of Narcissus c.v. "Bridal Crown".

Three-dimensional finite element modeling of a maxillary premolar tooth based on the micro-CT scanning: a detailed description.

PubMed

Huang, Zheng; Chen, Zhi

2013-10-01

This study describes the details of how to construct a three-dimensional (3D) finite element model of a maxillary first premolar tooth based on micro-CT data acquisition technique, MIMICS software and ANSYS software. The tooth was scanned by micro-CT, in which 1295 slices were obtained and then 648 slices were selected for modeling. The 3D surface mesh models of enamel and dentin were created by MIMICS (STL file). The solid mesh model was constructed by ANSYS. After the material properties and boundary conditions were set, a loading analysis was performed to demonstrate the applicableness of the resulting model. The first and third principal stresses were then evaluated. The results showed that the number of nodes and elements of the finite element model were 56 618 and 311801, respectively. The geometric form of the model was highly consistent with that of the true tooth, and the deviation between them was -0.28%. The loading analysis revealed the typical stress patterns in the contour map. The maximum compressive stress existed in the contact points and the maximum tensile stress existed in the deep fissure between the two cusps. It is concluded that by using the micro-CT and highly integrated software, construction of the 3D finite element model with high quality will not be difficult for clinical researchers.

Hybrid 3D-2D printing of bone scaffolds Hybrid 3D-2D printing methods for bone scaffolds fabrication.

PubMed

Prinz, V Ya; Seleznev, Vladimir

2016-12-13

It is a well-known fact that bone scaffold topography on micro- and nanometer scale influences the cellular behavior. Nano-scale surface modification of scaffolds allows the modulation of biological activity for enhanced cell differentiation. To date, there has been only a limited success in printing scaffolds with micro- and nano-scale features exposed on the surface. To improve on the currently available imperfect technologies, in our paper we introduce new hybrid technologies based on a combination of 2D (nano imprint) and 3D printing methods. The first method is based on using light projection 3D printing and simultaneous 2D nanostructuring of each of the layers during the formation of the 3D structure. The second method is based on the sequential integration of preliminarily created 2D nanostructured films into a 3D printed structure. The capabilities of the developed hybrid technologies are demonstrated with the example of forming 3D bone scaffolds. The proposed technologies can be used to fabricate complex 3D micro- and nanostructured products for various fields. Copyright 2016 IOP Publishing Ltd.

SU-F-T-664: The Efficacy of Gold Nanoparticles as Contrast Agents in Mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Y; Zhang, Y; Sajo, E

Purpose: Micro-Computed Tomography (micro-CT) has been widely used as a non-invasive, high-resolution imaging modality in preclinical research. However, tumors cannot be well distinguished, since their density are similar to those of surrounding tissues, and the tumors’ natural contrast is very low. The benefits of using Gold Nanoparticles (AuNPs) as a promising high atomic weight contrast agent have been published in recent years. The aim of this study is to investigate the efficacy of AuNPs as contrast agents using different energy x-rays. Methods: The left flank of an immune-compromised athymic nude mouse was implanted with subcutaneous xenograft model of human lungmore » cancer line, A549 cells (from ATCC). After 14 days, this mouse was imaged with dual energy cone-beam micro-CT. The selected energies were 45 kVp and 65 kVp. 10µg AuNPs (200 µg/ml concentration) approximately 12 nm in size were injected subcutaneously into the tumor. The mouse was imaged 0, 3 and 24 hours post-injection. During scanning, this mouse was anesthetized. All projection raw data have been optimized and then images were reconstructed with the FDK Algorithm. Results: Based on images, at 0 hour, AuNPs provided obvious contrast no matter which energy selected, 45 kVp or 65 kVp; and using 45 kVp X-ray, AuNps showed greater contrast. After 3 hours or evenand longer, AuNPs distributed throughout the whole body of mouse, and they were not shown clearly shown in the images. Conclusion: In this study, we investigated the efficacy of AuNPs as image contrast agents at different energies with dual-energy micro-CT, using 200µg/mL of AuNPs. Sufficiently high concentrations of AuNPs are needed to be able to track intratumoral distribution. Images showed good contrast immediately following the administration of the agent but results were poor after 3 hours.« less

Field-portable lensfree tomographic microscope†

PubMed Central

Isikman, Serhan O.; Bishara, Waheb; Sikora, Uzair; Yaglidere, Oguzhan; Yeah, John; Ozcan, Aydogan

2011-01-01

We present a field-portable lensfree tomographic microscope, which can achieve sectional imaging of a large volume (~20 mm3) on a chip with an axial resolution of <7 μm. In this compact tomographic imaging platform (weighing only ~110 grams), 24 light-emitting diodes (LEDs) that are each butt-coupled to a fibre-optic waveguide are controlled through a cost-effective micro-processor to sequentially illuminate the sample from different angles to record lensfree holograms of the sample that is placed on the top of a digital sensor array. In order to generate pixel super-resolved (SR) lensfree holograms and hence digitally improve the achievable lateral resolution, multiple sub-pixel shifted holograms are recorded at each illumination angle by electromagnetically actuating the fibre-optic waveguides using compact coils and magnets. These SR projection holograms obtained over an angular range of ~50° are rapidly reconstructed to yield projection images of the sample, which can then be back-projected to compute tomograms of the objects on the sensor-chip. The performance of this compact and light-weight lensfree tomographic microscope is validated by imaging micro-beads of different dimensions as well as a Hymenolepis nana egg, which is an infectious parasitic flatworm. Achieving a decent three-dimensional spatial resolution, this field-portable on-chip optical tomographic microscope might provide a useful toolset for telemedicine and high-throughput imaging applications in resource-poor settings. PMID:21573311

Identification of More Feasible MicroRNA-mRNA Interactions within Multiple Cancers Using Principal Component Analysis Based Unsupervised Feature Extraction.

PubMed

Taguchi, Y-H

2016-05-10

MicroRNA(miRNA)-mRNA interactions are important for understanding many biological processes, including development, differentiation and disease progression, but their identification is highly context-dependent. When computationally derived from sequence information alone, the identification should be verified by integrated analyses of mRNA and miRNA expression. The drawback of this strategy is the vast number of identified interactions, which prevents an experimental or detailed investigation of each pair. In this paper, we overcome this difficulty by the recently proposed principal component analysis (PCA)-based unsupervised feature extraction (FE), which reduces the number of identified miRNA-mRNA interactions that properly discriminate between patients and healthy controls without losing biological feasibility. The approach is applied to six cancers: hepatocellular carcinoma, non-small cell lung cancer, esophageal squamous cell carcinoma, prostate cancer, colorectal/colon cancer and breast cancer. In PCA-based unsupervised FE, the significance does not depend on the number of samples (as in the standard case) but on the number of features, which approximates the number of miRNAs/mRNAs. To our knowledge, we have newly identified miRNA-mRNA interactions in multiple cancers based on a single common (universal) criterion. Moreover, the number of identified interactions was sufficiently small to be sequentially curated by literature searches.

Irrigating poplar energy crops with landfill leachate negatively affects soil micro- and meso-fauna

Treesearch

David R. Coyle; Jill A. Zalesny; Ronald S. Zalesny Jr.; Adam H. Wiese

2011-01-01

Increased municipal solid waste generated worldwide combined with substantial demand for renewable energy has prompted testing and deployment of woody feedstock production systems that reuse and recycle wastewaters as irrigation and fertilization. Populus selections are ideal for such systems given their fast growth, extensive root systems, and high...

DNA strand-displacement-induced fluorescence enhancement for highly sensitive and selective assay of multiple microRNA in cancer cells.

PubMed

Wu, Ping; Tu, Yunqiu; Qian, Yingdan; Zhang, Hui; Cai, Chenxin

2014-01-28

We report a new strategy for evaluating multiple miRNA expressions in cancer cells based on DNA strand-displacement-induced fluorescence enhancement. This assay has the ability to discriminate the target from even single-base mismatched sequences or other miRNAs.

Deconstructing Evolution Education: The Relationship between Micro- and Macroevolution

ERIC Educational Resources Information Center

Novick, Laura R.; Schreiber, Emily G.; Catley, Kefyn M.

2014-01-01

With applications of Tree of Life data becoming ever more prevalent in everyday contexts, tree thinking has emerged as a vital component of scientific literacy. This article reports a study testing the hypothesis that instruction in natural selection, which is the primary focus of US evolution education at the high school and introductory college…

Mediation by SRIF1 receptors of the contractile action of somatostatin in rat isolated distal colon; studies using some novel SRIF analogues.

PubMed Central

McKeen, E S; Feniuk, W; Humphrey, P P

1994-01-01

1. The motor effects of somatostatin-14 (SRIF), and several SRIF peptide analogues were investigated on the rat isolated distal colon. The objective of these studies was to characterize the receptor mediating the contractile action of SRIF by comparing the relative agonist potencies of a range of SRIF analogues. 2. SRIF (1 nM-1 microM) produced concentration-dependent contractions with an EC50 value of approximately 10 nM. Contractile responses induced by SRIF were insensitive to atropine (1 microM) or naloxone (1 microM) but abolished by tetrodotoxin (1 microM). Somatostatin-28 (SRIF28), also induced concentration-dependent contractions and was equipotent with SRIF. Phosphoramidon (1 microM) and amastatin (10 microM) did not increase the potency of either SRIF or SRIF28. 3. The SRIF peptide analogues, octreotide, SRIF25, seglitide, angiopeptin and CGP23996 (1 nM-1 microM) produced contractile responses in the rat distal colon, each having similar potency and maximal activity relative to SRIF. The SSTR2 receptor-selective hexapeptide, BIM23027 (0.1 nM-1 microM), and the SRIF stereoisomer, D-Trp8-SRIF (0.1 nM-1 microM), were the most potent agonists examined being approximately 12 and 7 times more potent than SRIF, respectively. In contrast, the SSTR5 receptor-selective analogue, L362,855, was approximately 120 times weaker than SRIF, whilst the SSTR3 receptor-selective analogue, BIM23056, was inactive at concentrations up to 3 microM. 4. The putative SRIF receptor antagonist, (cyclo(7-aminoheptanoyl Phe-D-Trp-Lys-Thr[Bzl]))(CPP) (1 microM), had no agonist activity and had no effect on contractions induced by SRIF. 5. The contractile actions of BIM23027 and seglitide were subject to pronounced desensitization.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7834217

Synthesis of Au microwires by selective oxidation of Au–W thin-film composition spreads

PubMed Central

Hamann, Sven; Brunken, Hayo; Salomon, Steffen; Meyer, Robert; Savan, Alan; Ludwig, Alfred

2013-01-01

We report on the stress-induced growth of Au microwires out of a surrounding Au–W matrix by selective oxidation, in view of a possible application as ‘micro-Velcro’. The Au wires are extruded due to the high compressive stress in the tungsten oxide formed by oxidation of elemental W. The samples were fabricated as a thin-film materials library using combinatorial sputter deposition followed by thermal oxidation. Sizes and shapes of the Au microwires were investigated as a function of the W to Au ratio. The coherence length and stress state of the Au microwires were related to their shape and plastic deformation. Depending on the composition of the Au–W precursor, the oxidized samples showed regions with differently shaped Au microwires. The Au48W52 composition yielded wires with the maximum length to diameter ratio due to the high compressive stress in the tungsten oxide matrix. The values of wire length (35 μm) and diameter (2 μm) achieved at the Au48W52 composition are suitable for micro-Velcro applications. PMID:27877561

Structural and optical characterization of GaAs nano-crystals selectively grown on Si nano-tips by MOVPE.

PubMed

Skibitzki, Oliver; Prieto, Ivan; Kozak, Roksolana; Capellini, Giovanni; Zaumseil, Peter; Arroyo Rojas Dasilva, Yadira; Rossell, Marta D; Erni, Rolf; von Känel, Hans; Schroeder, Thomas

2017-03-01

We present the nanoheteroepitaxial growth of gallium arsenide (GaAs) on nano-patterned silicon (Si) (001) substrates fabricated using a CMOS technology compatible process. The selective growth of GaAs nano-crystals (NCs) was achieved at 570 °C by MOVPE. A detailed structure and defect characterization study of the grown nano-heterostructures was performed using scanning transmission electron microscopy, x-ray diffraction, micro-Raman, and micro-photoluminescence (μ-PL) spectroscopy. The results show single-crystalline, nearly relaxed GaAs NCs on top of slightly, by the SiO 2 -mask compressively strained Si nano-tips (NTs). Given the limited contact area, GaAs/Si nanostructures benefit from limited intermixing in contrast to planar GaAs films on Si. Even though a few growth defects (e.g. stacking faults, micro/nano-twins, etc) especially located at the GaAs/Si interface region were detected, the nanoheterostructures show intensive light emission, as investigated by μ-PL spectroscopy. Achieving well-ordered high quality GaAs NCs on Si NTs may provide opportunities for superior electronic, photonic, or photovoltaic device performances integrated on the silicon technology platform.

Movement plans for posture selection do not transfer across hands

PubMed Central

Schütz, Christoph; Schack, Thomas

2015-01-01

In a sequential task, the grasp postures people select depend on their movement history. This motor hysteresis effect results from the reuse of former movement plans and reduces the cognitive cost of movement planning. Movement plans for hand trajectories not only transfer across successive trials, but also across hands. We therefore asked whether such a transfer would also be found in movement plans for hand postures. To this end, we designed a sequential, continuous posture selection task. Participants had to open a column of drawers with cylindrical knobs in ascending and descending sequences. A hand switch was required in each sequence. Hand pro/supination was analyzed directly before and after the hand switch. Results showed that hysteresis effects were present directly before, but absent directly after the hand switch. This indicates that, in the current study, movement plans for hand postures only transfer across trials, but not across hands. PMID:26441734

Computational design and fabrication of core-shell magnetic molecularly imprinted polymer for dispersive micro-solid-phase extraction coupled with high-performance liquid chromatography for the determination of rhodamine 6G.

PubMed

Xie, Jin; Xie, Jie; Deng, Jian; Fang, Xiangfang; Zhao, Haiqing; Qian, Duo; Wang, Hongjuan

2016-06-01

A novel core-shell magnetic nano-adsorbent with surface molecularly imprinted polymer coating was fabricated and then applied to dispersive micro-solid-phase extraction followed by determination of rhodamine 6G using high-performance liquid chromatography. The molecularly imprinted polymer coating was prepared by copolymerization of dopamine and m-aminophenylboronic acid (functional monomers), in the presence of rhodamine 6G (template). The selection of the suitable functional monomers was based on the interaction between different monomers and the template using the density functional theory. The ratios of the monomers to template were further optimized by an OA9 (3(4) ) orthogonal array design. The binding performances of the adsorbent were evaluated by static, kinetic, and selective adsorption experiments. The results reveal that the adsorbent possesses remarkable affinity and binding specificity for rhodamine 6G because of the enhanced Lewis acid-base interaction between the B(Ш) embedded in the imprinted cavities and the template. The nano-adsorbent was successfully applied to dispersive micro-solid-phase extraction coupled to high-performance liquid chromatography for the trace determination of rhodamine 6G in samples with a detection limit of 2.7 nmol/L. Spiked recoveries ranged from 93.0-99.1, 89.5-92.7, and 86.9-105% in river water, matrimony vine and paprika samples, respectively, with relative standard deviations of less than 4.3%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ironstone deposits hosted in Eocene carbonates from Bahariya (Egypt)-New perspective on cherty ironstone occurrences

NASA Astrophysics Data System (ADS)

Afify, A. M.; Sanz-Montero, M. E.; Calvo, J. P.

2015-11-01

This paper gives new insight into the genesis of cherty ironstone deposits. The research was centered on well-exposed, unique cherty ironstone mineralization associated with Eocene carbonates from the northern part of the Bahariya Depression (Egypt). The economically important ironstones occur in the Naqb Formation (Early Eocene), which is mainly formed of shallow marine carbonate deposits. Periods of lowstand sea-level caused extensive early dissolution (karstification) of the depositional carbonates and dolomitization associated with mixing zones of fresh and marine pore-water. In faulted areas, the Eocene carbonate deposits were transformed into cherty ironstone with preservation of the precursor carbonate sedimentary features, i.e. skeletal and non-skeletal grain types, thickness, bedding, lateral and vertical sequential arrangement, and karst profiles. The ore deposits are composed of iron oxyhydroxides, mainly hematite and goethite, chert in the form of micro- to macro-quartz and chalcedony, various manganese minerals, barite, and a number of subordinate sulfate and clay minerals. Detailed petrographic analysis shows that quartz and iron oxides were coetaneous and selectively replaced carbonates, the coarse dolomite crystals having been preferentially transformed into quartz whereas the micro-crystalline carbonates were replaced by the iron oxyhydroxides. A number of petrographic, sedimentological and structural features including the presence of hydrothermal-mediated minerals (e.g., jacobsite), the geochemistry of the ore minerals as well as the structure-controlled location of the mineralization suggest a hydrothermal source for the ore-bearing fluids circulating through major faults and reflect their proximity to centers of magmatism. The proposed formation model can contribute to better understanding of the genetic mechanisms of formation of banded iron formations (BIFs) that were abundant during the Precambrian.

Microfabrication of channel arrays promotes vessel-like network formation in cardiac cell construct and vascularization in vivo.

PubMed

Zieber, Liran; Or, Shira; Ruvinov, Emil; Cohen, Smadar

2014-06-01

Pre-vascularization is important for the reconstruction of dense and metabolically active myocardial tissue and its integration with the host myocardium after implantation. Herein, we demonstrate that the fabrication of micro-channels in alginate scaffold combined with the presentation of adhesion peptides and an angiogenic growth factor promote vessel-like networks in the construct, both in vitro and in vivo. Using a CO2 laser engraving system, 200 µm diameter channels were formed from top to bottom of the 2 mm thick alginate scaffold, with a channel-to-channel distance of 400 µm. Cells were seeded in a sequential manner onto the scaffolds: first, human umbilical vascular endothelial cells (HUVECs) were seeded and cultured for three days, then neonatal rat cardiomyocytes (CMs) and cardiofibroblasts were added at a final cell ratio of 50:35:15, respectively, and the constructs were cultivated for an additional seven days. A vessel-like network was formed within the cell constructs, wherein HUVECs were organized around the channels in a multilayer manner, while the CMs were located in-between the channels and exhibited the characteristic morphological features of a mature cardiac fiber. Acellular scaffolds with the affinity-bound basic fibroblast growth factor were implanted subcutaneously in mice. Increased cell penetration into the channeled scaffold and greater vessel density were found in comparison with the nonchanneled scaffolds. Our results thus point to the importance of micro-channels as a major structural promoter of vascularization in scaffolds, in conjunction with the sequential preculture of ECs and angiogenic factor presentation.

Molecularly imprinted polymers based stir bar sorptive extraction for determination of cefaclor and cefalexin in environmental water.

PubMed

Peng, Jun; Liu, Donghao; Shi, Tian; Tian, Huairu; Hui, Xuanhong; He, Hua

2017-07-01

Although stir bar sportive extraction was thought to be a highly efficiency and simple pretreatment approach, its wide application was limited by low selectivity, short service life, and relatively high cost. In order to improve the performance of the stir bar, molecular imprinted polymers and magnetic carbon nanotubes were combined in the present study. In addition, two monomers were utilized to intensify the selectivity of molecularly imprinted polymers. Fourier transform infrared spectroscopy, scanning electron microscopy, and selectivity experiments showed that the molecularly imprinted polymeric stir bar was successfully prepared. Then micro-extraction based on the obtained stir bar was coupled with HPLC for determination of trace cefaclor and cefalexin in environmental water. This approach had the advantages of stir bar sportive extraction, high selectivity of molecular imprinted polymers, and high sorption efficiency of carbon nanotubes. To utilize this pretreatment approach, pH, extraction time, stirring speed, elution solvent, and elution time were optimized. The LOD and LOQ of cefaclor were found to be 3.5 ng · mL -1 and 12.0 ng · mL -1 , respectively; the LOD and LOQ of cefalexin were found to be 3.0 ng · mL -1 and 10.0 ng · mL -1 , respectively. The recoveries of cefaclor and cefalexin were 86.5 ~ 98.6%. The within-run precision and between-run precision were acceptable (relative standard deviation <7%). Even when utilized in more than 14 cycles, the performance of the stir bar did not decrease dramatically. This demonstrated that the molecularly imprinted polymeric stir bar based micro-extraction was a convenient, efficient, low-cost, and a specific method for enrichment of cefaclor and cefalexin in environmental samples.

A behavioural and neural evaluation of prospective decision-making under risk

PubMed Central

Symmonds, Mkael; Bossaerts, Peter; Dolan, Raymond J.

2010-01-01

Making the best choice when faced with a chain of decisions requires a person to judge both anticipated outcomes and future actions. Although economic decision-making models account for both risk and reward in single choice contexts there is a dearth of similar knowledge about sequential choice. Classical utility-based models assume that decision-makers select and follow an optimal pre-determined strategy, irrespective of the particular order in which options are presented. An alternative model involves continuously re-evaluating decision utilities, without prescribing a specific future set of choices. Here, using behavioral and functional magnetic resonance imaging (fMRI) data, we studied human subjects in a sequential choice task and use these data to compare alternative decision models of valuation and strategy selection. We provide evidence that subjects adopt a model of re-evaluating decision utilities, where available strategies are continuously updated and combined in assessing action values. We validate this model by using simultaneously-acquired fMRI data to show that sequential choice evokes a pattern of neural response consistent with a tracking of anticipated distribution of future reward, as expected in such a model. Thus, brain activity evoked at each decision point reflects the expected mean, variance and skewness of possible payoffs, consistent with the idea that sequential choice evokes a prospective evaluation of both available strategies and possible outcomes. PMID:20980595

Immortal time bias: a frequently unrecognized threat to validity in the evaluation of postoperative radiotherapy.

PubMed

Park, Henry S; Gross, Cary P; Makarov, Danil V; Yu, James B

2012-08-01

To evaluate the influence of immortal time bias on observational cohort studies of postoperative radiotherapy (PORT) and the effectiveness of sequential landmark analysis to account for this bias. First, we reviewed previous studies of the Surveillance, Epidemiology, and End Results (SEER) database to determine how frequently this bias was considered. Second, we used SEER to select three tumor types (glioblastoma multiforme, Stage IA-IVM0 gastric adenocarcinoma, and Stage II-III rectal carcinoma) for which prospective trials demonstrated an improvement in survival associated with PORT. For each tumor type, we calculated conditional survivals and adjusted hazard ratios of PORT vs. postoperative observation cohorts while restricting the sample at sequential monthly landmarks. Sixty-two percent of previous SEER publications evaluating PORT failed to use a landmark analysis. As expected, delivery of PORT for all three tumor types was associated with improved survival, with the largest associated benefit favoring PORT when all patients were included regardless of survival. Preselecting a cohort with a longer minimum survival sequentially diminished the apparent benefit of PORT. Although the majority of previous SEER articles do not correct for it, immortal time bias leads to altered estimates of PORT effectiveness, which are very sensitive to landmark selection. We suggest the routine use of sequential landmark analysis to account for this bias. Copyright © 2012 Elsevier Inc. All rights reserved.

Immortal Time Bias: A Frequently Unrecognized Threat to Validity in the Evaluation of Postoperative Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Henry S.; Gross, Cary P.; Makarov, Danil V.

2012-08-01

Purpose: To evaluate the influence of immortal time bias on observational cohort studies of postoperative radiotherapy (PORT) and the effectiveness of sequential landmark analysis to account for this bias. Methods and Materials: First, we reviewed previous studies of the Surveillance, Epidemiology, and End Results (SEER) database to determine how frequently this bias was considered. Second, we used SEER to select three tumor types (glioblastoma multiforme, Stage IA-IVM0 gastric adenocarcinoma, and Stage II-III rectal carcinoma) for which prospective trials demonstrated an improvement in survival associated with PORT. For each tumor type, we calculated conditional survivals and adjusted hazard ratios of PORTmore » vs. postoperative observation cohorts while restricting the sample at sequential monthly landmarks. Results: Sixty-two percent of previous SEER publications evaluating PORT failed to use a landmark analysis. As expected, delivery of PORT for all three tumor types was associated with improved survival, with the largest associated benefit favoring PORT when all patients were included regardless of survival. Preselecting a cohort with a longer minimum survival sequentially diminished the apparent benefit of PORT. Conclusions: Although the majority of previous SEER articles do not correct for it, immortal time bias leads to altered estimates of PORT effectiveness, which are very sensitive to landmark selection. We suggest the routine use of sequential landmark analysis to account for this bias.« less

A behavioral and neural evaluation of prospective decision-making under risk.

PubMed

Symmonds, Mkael; Bossaerts, Peter; Dolan, Raymond J

2010-10-27

Making the best choice when faced with a chain of decisions requires a person to judge both anticipated outcomes and future actions. Although economic decision-making models account for both risk and reward in single-choice contexts, there is a dearth of similar knowledge about sequential choice. Classical utility-based models assume that decision-makers select and follow an optimal predetermined strategy, regardless of the particular order in which options are presented. An alternative model involves continuously reevaluating decision utilities, without prescribing a specific future set of choices. Here, using behavioral and functional magnetic resonance imaging (fMRI) data, we studied human subjects in a sequential choice task and use these data to compare alternative decision models of valuation and strategy selection. We provide evidence that subjects adopt a model of reevaluating decision utilities, in which available strategies are continuously updated and combined in assessing action values. We validate this model by using simultaneously acquired fMRI data to show that sequential choice evokes a pattern of neural response consistent with a tracking of anticipated distribution of future reward, as expected in such a model. Thus, brain activity evoked at each decision point reflects the expected mean, variance, and skewness of possible payoffs, consistent with the idea that sequential choice evokes a prospective evaluation of both available strategies and possible outcomes.

Binding-induced DNA walker for signal amplification in highly selective electrochemical detection of protein.

PubMed

Ji, Yuhang; Zhang, Lei; Zhu, Longyi; Lei, Jianping; Wu, Jie; Ju, Huangxian

2017-10-15

A binding-induced DNA walker-assisted signal amplification was developed for highly selective electrochemical detection of protein. Firstly, the track of DNA walker was constructed by self-assembly of the high density ferrocene (Fc)-labeled anchor DNA and aptamer 1 on the gold electrode surface. Sequentially, a long swing-arm chain containing aptamer 2 and walking strand DNA was introduced onto gold electrode through aptamers-target specific recognition, and thus initiated walker strand sequences to hybridize with anchor DNA. Then, the DNA walker was activated by the stepwise cleavage of the hybridized anchor DNA by nicking endonuclease to release multiple Fc molecules for signal amplification. Taking thrombin as the model target, the Fc-generated electrochemical signal decreased linearly with logarithm value of thrombin concentration ranging from 10pM to 100nM with a detection limit of 2.5pM under the optimal conditions. By integrating the specific recognition of aptamers to target with the enzymatic cleavage of nicking endonuclease, the aptasensor showed the high selectivity. The binding-induced DNA walker provides a promising strategy for signal amplification in electrochemical biosensor, and has the extensive applications in sensitive and selective detection of the various targets. Copyright © 2017 Elsevier B.V. All rights reserved.

Highly sensitive and selective microRNA detection based on DNA-bio-bar-code and enzyme-assisted strand cycle exponential signal amplification.

PubMed

Dong, Haifeng; Meng, Xiangdan; Dai, Wenhao; Cao, Yu; Lu, Huiting; Zhou, Shufeng; Zhang, Xueji

2015-04-21

Herein, a highly sensitive and selective microRNA (miRNA) detection strategy using DNA-bio-bar-code amplification (BCA) and Nb·BbvCI nicking enzyme-assisted strand cycle for exponential signal amplification was designed. The DNA-BCA system contains a locked nucleic acid (LNA) modified DNA probe for improving hybridization efficiency, while a signal reported molecular beacon (MB) with an endonuclease recognition site was designed for strand cycle amplification. In the presence of target miRNA, the oligonucleotides functionalized magnetic nanoprobe (MNP-DNA) and gold nanoprobe (AuNP-DNA) with numerous reported probes (RP) can hybridize with target miRNA, respectively, to form a sandwich structure. After sandwich structures were separated from the solution by the magnetic field, the RP were released under high temperature to recognize the MB and cleaved the hairpin DNA to induce the dissociation of RP. The dissociated RP then triggered the next strand cycle to produce exponential fluorescent signal amplification for miRNA detection. Under optimized conditions, the exponential signal amplification system shows a good linear range of 6 orders of magnitude (from 0.3 pM to 3 aM) with limit of detection (LOD) down to 52.5 zM, while the sandwich structure renders the system with high selectivity. Meanwhile, the feasibility of the proposed strategy for cell miRNA detection was confirmed by analyzing miRNA-21 in HeLa lysates. Given the high-performance for miRNA analysis, the strategy has a promising application in biological detection and in clinical diagnosis.

Flexible sequential designs for multi-arm clinical trials.

PubMed

Magirr, D; Stallard, N; Jaki, T

2014-08-30

Adaptive designs that are based on group-sequential approaches have the benefit of being efficient as stopping boundaries can be found that lead to good operating characteristics with test decisions based solely on sufficient statistics. The drawback of these so called 'pre-planned adaptive' designs is that unexpected design changes are not possible without impacting the error rates. 'Flexible adaptive designs' on the other hand can cope with a large number of contingencies at the cost of reduced efficiency. In this work, we focus on two different approaches for multi-arm multi-stage trials, which are based on group-sequential ideas, and discuss how these 'pre-planned adaptive designs' can be modified to allow for flexibility. We then show how the added flexibility can be used for treatment selection and sample size reassessment and evaluate the impact on the error rates in a simulation study. The results show that an impressive overall procedure can be found by combining a well chosen pre-planned design with an application of the conditional error principle to allow flexible treatment selection. Copyright © 2014 John Wiley & Sons, Ltd.

Kavalactones and dihydrokavain modulate GABAergic activity in a rat gastric-brainstem preparation.

PubMed

Yuan, Chun-Su; Dey, Lucy; Wang, Anbao; Mehendale, Sangeeta; Xie, Jing-Tian; Aung, Han H; Ang-Lee, Michael K

2002-12-01

Using an in vitro neonatal rat gastric-brainstem preparation, the activity of majority neurons recorded in the nucleus tractus solitarius (NTS) of the brainstem were significantly inhibited by GABA A receptor agonist, muscimol (30 microM), and this inhibition was reversed by selective GABA A receptor antagonist, bicuculline (10 microM). Application of kavalactones (300 microg/ml) and dihydrokavain (300 microM) into the brainstem compartment of the preparation also significantly reduced the discharge rate of these NTS neurons (39 % and 32 %, respectively, compared to the control level), and this reduction was partially reversed by bicuculline (10 microM). Kavalactones or dihydrokavain induced inhibitory effects were not reduced after co-application of saclofen (10 microM; a selective GABA B receptor antagonist) or naloxone (100 nM; an opioid receptor antagonist). Pretreatment with kavalactones (300 microg/ml) or dihydrokavain (300 microM) significantly decreased the NTS inhibitory effects induced by muscimol (30 microM), approximately from 51 % to 36 %. Our results demonstrated modulation of brainstem GABAergic mechanism by kavalactones and dihydrokavain, and suggested that these compounds may play an important role in regulation of GABAergic neurotransmission.

An Iterative Approach for the Optimization of Pavement Maintenance Management at the Network Level

PubMed Central

Torres-Machí, Cristina; Chamorro, Alondra; Videla, Carlos; Yepes, Víctor

2014-01-01

Pavement maintenance is one of the major issues of public agencies. Insufficient investment or inefficient maintenance strategies lead to high economic expenses in the long term. Under budgetary restrictions, the optimal allocation of resources becomes a crucial aspect. Two traditional approaches (sequential and holistic) and four classes of optimization methods (selection based on ranking, mathematical optimization, near optimization, and other methods) have been applied to solve this problem. They vary in the number of alternatives considered and how the selection process is performed. Therefore, a previous understanding of the problem is mandatory to identify the most suitable approach and method for a particular network. This study aims to assist highway agencies, researchers, and practitioners on when and how to apply available methods based on a comparative analysis of the current state of the practice. Holistic approach tackles the problem considering the overall network condition, while the sequential approach is easier to implement and understand, but may lead to solutions far from optimal. Scenarios defining the suitability of these approaches are defined. Finally, an iterative approach gathering the advantages of traditional approaches is proposed and applied in a case study. The proposed approach considers the overall network condition in a simpler and more intuitive manner than the holistic approach. PMID:24741352

An iterative approach for the optimization of pavement maintenance management at the network level.

PubMed

Torres-Machí, Cristina; Chamorro, Alondra; Videla, Carlos; Pellicer, Eugenio; Yepes, Víctor

2014-01-01

Pavement maintenance is one of the major issues of public agencies. Insufficient investment or inefficient maintenance strategies lead to high economic expenses in the long term. Under budgetary restrictions, the optimal allocation of resources becomes a crucial aspect. Two traditional approaches (sequential and holistic) and four classes of optimization methods (selection based on ranking, mathematical optimization, near optimization, and other methods) have been applied to solve this problem. They vary in the number of alternatives considered and how the selection process is performed. Therefore, a previous understanding of the problem is mandatory to identify the most suitable approach and method for a particular network. This study aims to assist highway agencies, researchers, and practitioners on when and how to apply available methods based on a comparative analysis of the current state of the practice. Holistic approach tackles the problem considering the overall network condition, while the sequential approach is easier to implement and understand, but may lead to solutions far from optimal. Scenarios defining the suitability of these approaches are defined. Finally, an iterative approach gathering the advantages of traditional approaches is proposed and applied in a case study. The proposed approach considers the overall network condition in a simpler and more intuitive manner than the holistic approach.

Potential and limitations of X-Ray micro-computed tomography in arthropod neuroanatomy: A methodological and comparative survey

PubMed Central

Sombke, Andy; Lipke, Elisabeth; Michalik, Peter; Uhl, Gabriele; Harzsch, Steffen

2015-01-01

Classical histology or immunohistochemistry combined with fluorescence or confocal laser scanning microscopy are common techniques in arthropod neuroanatomy, and these methods often require time-consuming and difficult dissections and sample preparations. Moreover, these methods are prone to artifacts due to compression and distortion of tissues, which often result in information loss and especially affect the spatial relationships of the examined parts of the nervous system in their natural anatomical context. Noninvasive approaches such as X-ray micro-computed tomography (micro-CT) can overcome such limitations and have been shown to be a valuable tool for understanding and visualizing internal anatomy and structural complexity. Nevertheless, knowledge about the potential of this method for analyzing the anatomy and organization of nervous systems, especially of taxa with smaller body size (e.g., many arthropods), is limited. This study set out to analyze the brains of selected arthropods with micro-CT, and to compare these results with available histological and immunohistochemical data. Specifically, we explored the influence of different sample preparation procedures. Our study shows that micro-CT is highly suitable for analyzing arthropod neuroarchitecture in situ and allows specific neuropils to be distinguished within the brain to extract quantitative data such as neuropil volumes. Moreover, data acquisition is considerably faster compared with many classical histological techniques. Thus, we conclude that micro-CT is highly suitable for targeting neuroanatomy, as it reduces the risk of artifacts and is faster than classical techniques. J. Comp. Neurol. 523:1281–1295, 2015. © 2015 Wiley Periodicals, Inc. PMID:25728683

Sequential and simultaneous choices: testing the diet selection and sequential choice models.

PubMed

Freidin, Esteban; Aw, Justine; Kacelnik, Alex

2009-03-01

We investigate simultaneous and sequential choices in starlings, using Charnov's Diet Choice Model (DCM) and Shapiro, Siller and Kacelnik's Sequential Choice Model (SCM) to integrate function and mechanism. During a training phase, starlings encountered one food-related option per trial (A, B or R) in random sequence and with equal probability. A and B delivered food rewards after programmed delays (shorter for A), while R ('rejection') moved directly to the next trial without reward. In this phase we measured latencies to respond. In a later, choice, phase, birds encountered the pairs A-B, A-R and B-R, the first implementing a simultaneous choice and the second and third sequential choices. The DCM predicts when R should be chosen to maximize intake rate, and SCM uses latencies of the training phase to predict choices between any pair of options in the choice phase. The predictions of both models coincided, and both successfully predicted the birds' preferences. The DCM does not deal with partial preferences, while the SCM does, and experimental results were strongly correlated to this model's predictions. We believe that the SCM may expose a very general mechanism of animal choice, and that its wider domain of success reflects the greater ecological significance of sequential over simultaneous choices.

Signal-on fluorescence biosensor for microRNA-21 detection based on DNA strand displacement reaction and Mg2+-dependent DNAzyme cleavage.

PubMed

Yin, Huan-Shun; Li, Bing-Chen; Zhou, Yun-Lei; Wang, Hai-Yan; Wang, Ming-Hui; Ai, Shi-Yun

2017-10-15

MicroRNAs have been involved into many biological processes and are regarded as disease biomarkers. Simple, rapid, sensitive and selective method for microRNA detection is crucial for early diagnosis and therapy of diseases. In this work, sensitive fluorescence assay was developed for microRNA-21 detection based on DNA polymerase induced strand displacement amplification reaction, Mg 2+ -dependent DNAzyme catalysis reaction, and magnetic separation. In the presence of target microRNA-21, amounts of trigger DNA could be produced with DNA polymerase induced strand displacement amplification reaction, and the trigger DNA could be further hybridized with signal DNA, which was labeled with biotin and AMCA dye. After introduction of Mg 2+ , trigger DNA could form DNAzyme to cleave signal DNA. After magnetic separation, the DNA fragment with AMCA dye could give fluorescence signal, which was related to microRNA-21 concentration. Based on the two efficient signal amplifications, the developed method showed high detection sensitivity with low detection limit of 0.27fM (3σ). In addition, this fluorescence strategy also possessed excellent detection specificity, and could be applied to analyze microRNA-21 expression level in serum of cancer patient. According to the obtained results, the developed fluorescence method might be a promising detection platform for microRNA-21 quantitative analysis in biomedical research and clinical diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of a physics teacher's pedagogical `micro-actions' that support 17-year-olds' learning of free body diagrams via a modelling approach

NASA Astrophysics Data System (ADS)

Tay, Su Lynn; Yeo, Jennifer

2018-01-01

Great teaching is characterised by the specific actions a teacher takes in the classroom to bring about learning. In the context of model-based teaching (MBT), teachers' difficulty in working with students' models that are not scientifically consistent is troubling. To address this problem, the aim of this study is to identify the pedagogical micro-actions to support the development of scientific models and modelling skills during the evaluation and modification stages of MBT. Taking the perspective of pedagogical content knowing (PCKg), it identifies these micro-actions as an in-situ, dynamic transformation of knowledges of content, pedagogy, student and environment context. Through a case study approach, a lesson conducted by an experienced high-school physics teacher was examined. Audio and video recordings of the lesson contributed to the data sources. Taking a grounded approach in the analysis, eight pedagogical micro-actions enacted by the teacher were identified, namely 'clarification', 'evaluation', 'explanation', 'modification', 'exploration', 'referencing conventions', 'focusing' and 'meta-representing'. These micro-actions support students' learning related to the conceptual, cognitive, discursive and epistemological aspects of modelling. From the micro-actions, we identify the aspects of knowledges of PCKg that teachers need in order to competently select and enact these micro-actions. The in-situ and dynamic transformation of these knowledges implies that professional development should also be situated in the context in which these micro-actions are meaningful.

One-pot growth of two-dimensional lateral heterostructures via sequential edge-epitaxy

NASA Astrophysics Data System (ADS)

Sahoo, Prasana K.; Memaran, Shahriar; Xin, Yan; Balicas, Luis; Gutiérrez, Humberto R.

2018-01-01

Two-dimensional heterojunctions of transition-metal dichalcogenides have great potential for application in low-power, high-performance and flexible electro-optical devices, such as tunnelling transistors, light-emitting diodes, photodetectors and photovoltaic cells. Although complex heterostructures have been fabricated via the van der Waals stacking of different two-dimensional materials, the in situ fabrication of high-quality lateral heterostructures with multiple junctions remains a challenge. Transition-metal-dichalcogenide lateral heterostructures have been synthesized via single-step, two-step or multi-step growth processes. However, these methods lack the flexibility to control, in situ, the growth of individual domains. In situ synthesis of multi-junction lateral heterostructures does not require multiple exchanges of sources or reactors, a limitation in previous approaches as it exposes the edges to ambient contamination, compromises the homogeneity of domain size in periodic structures, and results in long processing times. Here we report a one-pot synthetic approach, using a single heterogeneous solid source, for the continuous fabrication of lateral multi-junction heterostructures consisting of monolayers of transition-metal dichalcogenides. The sequential formation of heterojunctions is achieved solely by changing the composition of the reactive gas environment in the presence of water vapour. This enables selective control of the water-induced oxidation and volatilization of each transition-metal precursor, as well as its nucleation on the substrate, leading to sequential edge-epitaxy of distinct transition-metal dichalcogenides. Photoluminescence maps confirm the sequential spatial modulation of the bandgap, and atomic-resolution images reveal defect-free lateral connectivity between the different transition-metal-dichalcogenide domains within a single crystal structure. Electrical transport measurements revealed diode-like responses across the junctions. Our new approach offers greater flexibility and control than previous methods for continuous growth of transition-metal-dichalcogenide-based multi-junction lateral heterostructures. These findings could be extended to other families of two-dimensional materials, and establish a foundation for the development of complex and atomically thin in-plane superlattices, devices and integrated circuits.

Sequential feature selection for detecting buried objects using forward looking ground penetrating radar

NASA Astrophysics Data System (ADS)

Shaw, Darren; Stone, Kevin; Ho, K. C.; Keller, James M.; Luke, Robert H.; Burns, Brian P.

2016-05-01

Forward looking ground penetrating radar (FLGPR) has the benefit of detecting objects at a significant standoff distance. The FLGPR signal is radiated over a large surface area and the radar signal return is often weak. Improving detection, especially for buried in road targets, while maintaining an acceptable false alarm rate remains to be a challenging task. Various kinds of features have been developed over the years to increase the FLGPR detection performance. This paper focuses on investigating the use of as many features as possible for detecting buried targets and uses the sequential feature selection technique to automatically choose the features that contribute most for improving performance. Experimental results using data collected at a government test site are presented.

Involvement of Working Memory in College Students' Sequential Pattern Learning and Performance

ERIC Educational Resources Information Center

Kundey, Shannon M. A.; De Los Reyes, Andres; Rowan, James D.; Lee, Bern; Delise, Justin; Molina, Sabrina; Cogdill, Lindsay

2013-01-01

When learning highly organized sequential patterns of information, humans and nonhuman animals learn rules regarding the hierarchical structures of these sequences. In three experiments, we explored the role of working memory in college students' sequential pattern learning and performance in a computerized task involving a sequential…

Disulfiram treatment increases plasma and red blood cell acetaldehyde in abstinent alcoholics.

PubMed

Rosman, A S; Waraich, A; Baraona, E; Lieber, C S

2000-07-01

Much of alcohol's toxicity is due to its product, acetaldehyde. The role of acetaldehyde derived from endogenous sources was assessed in alcoholic patients administered disulfiram, an inhibitor of aldehyde dehydrogenase. The first part of the study included 23 subjects without biochemical or clinical evidence of chronic liver disease who were abstinent for 2 weeks; 11 patients were started on disulfiram (250 mg/day), whereas the other 12 were not given disulfiram and served as controls. The second part of the study included 13 alcoholic patients with clinical or pathological evidence of cirrhosis who also were administered disulfiram for 2 weeks. Plasma and red blood cell (RBC) acetaldehyde as well as serum transaminases were measured at baseline and after 1 and 2 weeks of treatment. In the disulfiram-treated group of alcoholics without known cirrhosis, RBC acetaldehyde levels increased from the pretreatment value of 2.98+/-0.18 microM to 4.14+/-0.33 microM after 1 week and to 4.14+/-0.26 microM after 2 weeks of treatment (p < 0.001). Compared with the pretreatment values (2.07+/-0.24 microM), plasma acetaldehyde levels also increased after 1 week (3.18+/-0.32 microM) and 2 weeks (3.15+/-0.26 microM) of disulfiram treatment (p < 0.001). There were no significant differences in sequential levels measured in either plasma or RBC acetaldehyde levels in patients who were not administered disulfiram. In the group of cirrhotic patients, the mean baseline RBC acetaldehyde value (3.60+/-0.22 microM) was significantly higher than in noncirrhotics. Disulfiram therapy increased the RBC acetaldehyde after 1 week (4.63+/-0.27 microM, p < 0.001) and 2 weeks of treatment (4.06+/-0.28 microM, p < 0.05). Compared with baseline values, plasma acetaldehyde levels were significantly higher after 1 week but not after 2 weeks of disulfiram. There were no significant differences among serum transaminases in alcoholics administered disulfiram, although three cirrhotic patients did have clinically significant elevations. In abstaining subjects given disulfiram, acetaldehyde concentrations increase, possibly due to diminished catabolism of endogenously generated acetaldehyde. Disulfiram should be given cautiously, especially in patients with cirrhosis.

The amphiphilic peptide adenoregulin enhances agonist binding to A1-adenosine receptors and [35S]GTP gamma S to brain membranes.

PubMed

Moni, R W; Romero, F S; Daly, J W

1995-08-01

1. Adenoregulin is an amphilic peptide isolated from skin mucus of the tree frog, Phyllomedusa bicolor. Synthetic adenoregulin enhanced the binding of agonists to several G-protein-coupled receptors in rat brain membranes. 2. The maximal enhancement of agonist binding, and in parentheses, the concentration of adenoregulin affording maximal enhancement were as follows: 60% (20 microM) for A1-adenosine receptors, 30% (100 microM) for A2a-adenosine receptors, 20% (2 microM) for alpha 2-adrenergic receptors, and 30% (10 microM) for 5HT1A receptors. High affinity agonist binding for A1-, alpha 2-, and 5HT1A-receptors was virtually abolished by GTP gamma S in the presence of adenoregulin, but was only partially abolished in its absence. Magnesium ions increased the binding of agonists to receptors and reduced the enhancement elicited by adenoregulin. 3. The effect of adenoregulin on binding of N6-cyclohexyladenosine ([3H]CHA) to A1-receptors was relatively slow and was irreversible. Adenoregulin increased the Bmax value for [3H]CHA binding sites, and the proportion of high affinity states, and slowed the rate of [3H]CHA dissociation. Binding of the A1-selective antagonist, [3H]DPCPX, was maximally enhanced by only 13% at 2 microM adenoregulin. Basal and A1-adenosine receptor-stimulated binding of [35S]GTP gamma S were maximally enhanced 45% and 23%, respectively, by 50 microM adenoregulin. In CHAPS-solubilized membranes from rat cortex, the binding of both [3H]CHA and [3H]DPCPX were enhanced by adenoregulin. Binding of [3H]CHA to membranes from DDT1 MF-2 cells was maximally enhanced 17% at 20 microM adenoregulin. In intact DDT1 MF-2 cells, 20 microM adenoregulin did not potentiate the inhibition of cyclic AMP accumulation mediated via the adenosine A1 receptor. 4. It is proposed that adenoregulin enhances agonist binding through a mechanism involving enhancement of guanyl nucleotide exchange at G-proteins, resulting in a conversion of receptors into a high affinity state complexed with guanyl nucleotide-free G-protein.

Nutrient recovery from the dry grind process using sequential micro and ultrafiltration of thin stillage.

PubMed

Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

2010-06-01

The effectiveness of microfiltration (MF) and ultrafiltration (UF) for nutrient recovery from a thin stillage stream was determined. When a stainless steel MF membrane (0.1microm pore size) was used, the content of solids increased from 7.0% to 22.8% with a mean permeate flux rate of 45L/m(2)/h (LMH), fat increased and ash content decreased. UF experiments were conducted in batch mode under constant temperature and flow rate conditions. Permeate flux profiles were evaluated for regenerated cellulose membranes (YM1, YM10 and YM100) with molecular weight cut offs of 1, 10 and 100kDa. UF increased total solids, protein and fat and decreased ash in retentate stream. When permeate streams from MF were subjected to UF, retentate total solids concentrations similar to those of commercial syrup (23-28.8%) were obtained. YM100 had the highest percent permeate flux decline (70% of initial flux) followed by YM10 and YM1 membranes. Sequential filtration improved permeate flux rates of the YM100 membrane (32.6-73.4LMH) but the percent decline was also highest in a sequential MF+YM100 system. Protein recovery was the highest in YM1 retentate. Removal of solids, protein and fat from thin stillage may generate a permeate stream that may improve water removal efficiency and increase water recycling. Copyright 2010 Elsevier Ltd. All rights reserved.

A Randomised Trial of empiric 14-day Triple, five-day Concomitant, and ten-day Sequential Therapies for Helicobacter pylori in Seven Latin American Sites

PubMed Central

Greenberg, E. Robert; Anderson, Garnet L.; Morgan, Douglas R.; Torres, Javier; Chey, William D.; Bravo, Luis Eduardo; Dominguez, Ricardo L.; Ferreccio, Catterina; Herrero, Rolando; Lazcano-Ponce, Eduardo C.; Meza-Montenegro, Mercedes María; Peña, Rodolfo; Peña, Edgar M.; Salazar-Martínez, Eduardo; Correa, Pelayo; Martínez, María Elena; Valdivieso, Manuel; Goodman, Gary E.; Crowley, John J.; Baker, Laurence H.

2011-01-01

Summary Background Evidence from Europe, Asia, and North America suggests that standard three-drug regimens of a proton pump inhibitor plus amoxicillin and clarithromycin are significantly less effective for eradicating Helicobacter pylori (H. pylori) infection than five-day concomitant and ten-day sequential four-drug regimens that include a nitroimidazole. These four-drug regimens also entail fewer antibiotic doses and thus may be suitable for eradication programs in low-resource settings. Studies are limited from Latin America, however, where the burden of H. pylori-associated diseases is high. Methods We randomised 1463 men and women ages 21–65 selected from general populations in Chile, Colombia, Costa Rica, Honduras, Nicaragua, and Mexico (two sites) who tested positive for H. pylori by a urea breath test (UBT) to: 14 days of lansoprazole, amoxicillin, and clarithromycin (standard therapy); five days of lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant therapy); or five days of lansoprazole and amoxicillin followed by five of lansoprazole, clarithromycin, and metronidazole (sequential therapy). Eradication was assessed by UBT six–eight weeks after randomisation. Findings In intention-to-treat analyses, the probability of eradication with standard therapy was 82·2%, which was 8·6% higher (95% adjusted CI: 2·6%, 14·5%) than with concomitant therapy (73·6%) and 5·6% higher (95% adjusted CI: −0·04%, 11·6%) than with sequential therapy (76·5%). In analyses limited to the 1314 participants who adhered to their assigned therapy, the probabilities of eradication were 87·1%, 78·7%, and 81·1% with standard, concomitant, and sequential therapies, respectively. Neither four-drug regimen was significantly better than standard triple therapy in any of the seven sites. Interpretation Standard 14-day triple-drug therapy is preferable to five-day concomitant or ten-day sequential four-drug regimens as empiric therapy for H. pylori among diverse Latin American populations. Funding Bill & Melinda Gates Foundation and US National Institutes of Health. PMID:21777974

Suppressing correlations in massively parallel simulations of lattice models

NASA Astrophysics Data System (ADS)

Kelling, Jeffrey; Ódor, Géza; Gemming, Sibylle

2017-11-01

For lattice Monte Carlo simulations parallelization is crucial to make studies of large systems and long simulation time feasible, while sequential simulations remain the gold-standard for correlation-free dynamics. Here, various domain decomposition schemes are compared, concluding with one which delivers virtually correlation-free simulations on GPUs. Extensive simulations of the octahedron model for 2 + 1 dimensional Kardar-Parisi-Zhang surface growth, which is very sensitive to correlation in the site-selection dynamics, were performed to show self-consistency of the parallel runs and agreement with the sequential algorithm. We present a GPU implementation providing a speedup of about 30 × over a parallel CPU implementation on a single socket and at least 180 × with respect to the sequential reference.

Three-dimensional device characterization by high-speed cinematography

NASA Astrophysics Data System (ADS)

Maier, Claus; Hofer, Eberhard P.

2001-10-01

Testing of micro-electro-mechanical systems (MEMS) for optimization purposes or reliability checks can be supported by device visualization whenever an optical access is available. The difficulty in such an investigation is the short time duration of dynamical phenomena in micro devices. This paper presents a test setup to visualize movements within MEMS in real-time and in two perpendicular directions. A three-dimensional view is achieved by the combination of a commercial high-speed camera system, which allows to take up to 8 images of the same process with a minimum interframe time of 10 ns for the first direction, with a second visualization system consisting of a highly sensitive CCD camera working with a multiple exposure LED illumination in the perpendicular direction. Well synchronized this provides 3-D information which is treated by digital image processing to correct image distortions and to perform the detection of object contours. Symmetric and asymmetric binary collisions of micro drops are chosen as test experiments, featuring coalescence and surface rupture. Another application shown here is the investigation of sprays produced by an atomizer. The second direction of view is a prerequisite for this measurement to select an intended plane of focus.

Online feature selection with streaming features.

PubMed

Wu, Xindong; Yu, Kui; Ding, Wei; Wang, Hao; Zhu, Xingquan

2013-05-01

We propose a new online feature selection framework for applications with streaming features where the knowledge of the full feature space is unknown in advance. We define streaming features as features that flow in one by one over time whereas the number of training examples remains fixed. This is in contrast with traditional online learning methods that only deal with sequentially added observations, with little attention being paid to streaming features. The critical challenges for Online Streaming Feature Selection (OSFS) include 1) the continuous growth of feature volumes over time, 2) a large feature space, possibly of unknown or infinite size, and 3) the unavailability of the entire feature set before learning starts. In the paper, we present a novel Online Streaming Feature Selection method to select strongly relevant and nonredundant features on the fly. An efficient Fast-OSFS algorithm is proposed to improve feature selection performance. The proposed algorithms are evaluated extensively on high-dimensional datasets and also with a real-world case study on impact crater detection. Experimental results demonstrate that the algorithms achieve better compactness and higher prediction accuracy than existing streaming feature selection algorithms.

Prospectivity Modeling of Karstic Groundwater Using a Sequential Exploration Approach in Tepal Area, Iran

NASA Astrophysics Data System (ADS)

Sharifi, Fereydoun; Arab-Amiri, Ali Reza; Kamkar-Rouhani, Abolghasem; Yousefi, Mahyar; Davoodabadi-Farahani, Meysam

2017-09-01

The purpose of this study is water prospectivity modeling (WPM) for recognizing karstic water-bearing zones by using analyses of geo-exploration data in Kal-Qorno valley, located in Tepal area, north of Iran. For this, a sequential exploration method applied on geo-evidential data to delineate target areas for further exploration. In this regard, two major exploration phases including regional and local scales were performed. In the first phase, indicator geological features, structures and lithological units, were used to model groundwater prospectivity as a regional scale. In this phase, for karstic WPM, fuzzy lithological and structural evidence layers were generated and combined using fuzzy operators. After generating target areas using WPM, in the second phase geophysical surveys including gravimetry and geoelectrical resistivity were carried out on the recognized high potential zones as a local scale exploration. Finally the results of geophysical analyses in the second phase were used to select suitable drilling locations to access and extract karstic groundwater in the study area.

Quantification of small GTPase glucosylation by clostridial glucosylating toxins using multiplexed MRM analysis.

PubMed

Junemann, Johannes; Lämmerhirt, Chantal M; Polten, Felix; Just, Ingo; Gerhard, Ralf; Genth, Harald; Pich, Andreas

2017-05-01

Large clostridial toxins mono-O-glucosylate small GTPases of the Rho and Ras subfamily. As a result of glucosylation, the GTPases are inhibited and thereby corresponding downstream signaling pathways are disturbed. Current methods for quantifying the extent of glucosylation include sequential [ 14 C]glucosylation, sequential [ 32 P]ADP-ribosylation, and Western Blot detection of nonglucosylated GTPases, with neither method allowing the quantification of the extent of glucosylation of an individual GTPase. Here, we describe a novel MS-based multiplexed MRM assay to specifically quantify the glucosylation degree of small GTPases. This targeted proteomics approach achieves a high selectivity and reproducibility, which allows determination of the in vivo substrate pattern of glucosylating toxins. As proof of principle, GTPase glucosylation was analyzed in CaCo-2 cells treated with TcdA, and glucosylation kinetics were determined for RhoA/B, RhoC, RhoG, Ral, Rap1, Rap2, (H/K/N)Ras, and R-Ras2. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On the role of verbalization during task set selection: switching or serial order control?

PubMed

Bryck, Richard L; Mayr, Ulrich

2005-06-01

Recent task-switching work in which paper-and-pencil administered single-task lists were compared with task-alternation lists has demonstrated large increases in task-switch costs with concurrent articulatory suppression (AS), implicating a crucial role for verbalization during switching (Baddeley, Chincotta, & Adlam, 2001; Emerson & Miyake, 2003). Experiment 1 replicated this result, using computerized assessment, albeit with much smaller effect sizes than in the original reports. In Experiment 2, AS interference was reduced when a sequential cue (spatial location) that indicated the current position in the sequence of task alternations was given. Finally, in Experiment 3, switch trials and no-switch trials were compared within a block of alternating runs of two tasks. Again, AS interference was obtained mainly when the endogenous sequencing demand was high, and it was comparable for no-switch and switch trials. These results suggest that verbalization may be critical for endogenous maintenance and updating of a sequential plan, rather than exclusively for the actual switching process.

Mechanistic Understanding of Tungsten Oxide In-Plane Nanostructure Growth via Sequential Infiltration Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jae Jin; Suh, Hyo Seon; Zhou, Chun

Tungsten oxide (WO3-x) nanostructures with hexagonal in-plane arrangements were fabricated by sequential infiltration synthesis (SIS), using the selective interaction of gas phase precursors with functional groups in one domain of a block copolymer (BCP) self-assembled template. Such structures are highly desirable for various practical applications and as model systems for fundamental studies. The nanostructures were characterized by cross-sectional scanning electron microscopy, grazing-incidence small/wide-angle X-ray scattering (GISAXS/GIWAXS), and X-ray absorption near edge structure (XANES) measurements at each stage during the SIS process and subsequent thermal treatments, to provide a comprehensive picture of their evolution in morphology, crystallography and electronic structure. Inmore » particular, we discuss the critical role of SIS Al2O3 seeds toward modifying the chemical affinity and free volume in a polymer for subsequent infiltration of gas phase precursors. The insights into SIS growth obtained from this study are valuable to the design and fabrication of a wide range of targeted nanostructures.« less

Clinical experience with trimegestone as a new progestin in HRT.

PubMed

Grubb, Gary; Spielmann, Daniele; Pickar, James; Constantine, Ginger

2003-11-01

Trimegestone (TMG) is a novel, 19-norpregnane progestin, which demonstrates endometrial selectivity with a reduced progestin-related side effect profile when compared to several other currently marketed progestins. TMG has been studied in combination with 17beta-estradiol (17beta-E2) and conjugated equine estrogens (CEE). TMG-containing HRT agents were effective in relieving vasomotor symptoms and providing protection from endometrial hyperplasia with < or =1% hyperplasia. In clinical trials with sequential regimens, TMG provided predictable withdrawal bleeding associated with a low incidence of irregular and prolonged bleeding. Clinical studies of continuous combined regimens of estrogen/TMG combinations demonstrated high levels of amenorrhea. Both 17beta-E2 and CEE/TMG combinations have shown improved bone mineral density and quality-of-life assessments. Both continuous combined and sequential regimens of 17beta-E2/TMG and CEE/TMG have a favorable clinical profile. TMG provides an important new option for the treatment of postmenopausal symptoms and the prevention of osteoporosis.

All-solid-state flexible ultrathin micro-supercapacitors based on graphene.

PubMed

Niu, Zhiqiang; Zhang, Li; Liu, Lili; Zhu, Bowen; Dong, Haibo; Chen, Xiaodong

2013-08-07

Flexible, compact, ultrathin and all-solid-state micro-supercapacitors are prepared by coating H₃PO₄/PVA gel electrolyte onto micro-patterned rGO interdigitated electrodes prepared by combining photolithography with selective electrophoretic deposition. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Item Selection Criteria with Practical Constraints for Computerized Classification Testing

ERIC Educational Resources Information Center

Lin, Chuan-Ju

2011-01-01

This study compares four item selection criteria for a two-category computerized classification testing: (1) Fisher information (FI), (2) Kullback-Leibler information (KLI), (3) weighted log-odds ratio (WLOR), and (4) mutual information (MI), with respect to the efficiency and accuracy of classification decision using the sequential probability…

Item Selection in Multidimensional Computerized Adaptive Testing--Gaining Information from Different Angles

ERIC Educational Resources Information Center

Wang, Chun; Chang, Hua-Hua

2011-01-01

Over the past thirty years, obtaining diagnostic information from examinees' item responses has become an increasingly important feature of educational and psychological testing. The objective can be achieved by sequentially selecting multidimensional items to fit the class of latent traits being assessed, and therefore Multidimensional…

Mutual Information Item Selection in Adaptive Classification Testing

ERIC Educational Resources Information Center

Weissman, Alexander

2007-01-01

A general approach for item selection in adaptive multiple-category classification tests is provided. The approach uses mutual information (MI), a special case of the Kullback-Leibler distance, or relative entropy. MI works efficiently with the sequential probability ratio test and alleviates the difficulties encountered with using other local-…

Adaptive web sampling.

PubMed

Thompson, Steven K

2006-12-01

A flexible class of adaptive sampling designs is introduced for sampling in network and spatial settings. In the designs, selections are made sequentially with a mixture distribution based on an active set that changes as the sampling progresses, using network or spatial relationships as well as sample values. The new designs have certain advantages compared with previously existing adaptive and link-tracing designs, including control over sample sizes and of the proportion of effort allocated to adaptive selections. Efficient inference involves averaging over sample paths consistent with the minimal sufficient statistic. A Markov chain resampling method makes the inference computationally feasible. The designs are evaluated in network and spatial settings using two empirical populations: a hidden human population at high risk for HIV/AIDS and an unevenly distributed bird population.

Development of high-accuracy convection schemes for sequential solvers

NASA Technical Reports Server (NTRS)

Thakur, Siddharth; Shyy, Wei

1993-01-01

An exploration is conducted of the applicability of such high resolution schemes as TVD to the resolving of sharp flow gradients using a sequential solution approach borrowed from pressure-based algorithms. It is shown that by extending these high-resolution shock-capturing schemes to a sequential solver that treats the equations as a collection of scalar conservation equations, the speed of signal propagation in the solution has to be coordinated by assigning the local convection speed as the characteristic speed for the entire system. A higher amount of dissipation is therefore needed to eliminate oscillations near discontinuities.

Laser speckle technique for burner liner strain measurements

NASA Technical Reports Server (NTRS)

Stetson, K. A.

1982-01-01

Thermal and mechanical strains were measured on samples of a common material used in jet engine burner liners, which were heated from room temperature to 870 C and cooled back to 220 C, in a laboratory furnance. The physical geometry of the sample surface was recorded at selected temperatures by a set of 12 single exposure speckle-grams. Sequential pairs of specklegrams were compared in a heterodyne interferometer which give high precision measurement of differential displacements. Good speckle correlation between the first and last specklegrams is noted which allows a check on accumulate errors.

Wavelength-division and spatial multiplexing using tandem interferometers for Bragg grating sensor networks

NASA Astrophysics Data System (ADS)

Kalli, K.; Brady, G. P.; Webb, D. J.; Jackson, D. A.; Zhang, L.; Bennion, I.

1995-12-01

We present a new method for the interrogation of large arrays of Bragg grating sensors. Eight gratings operating between the wavelengths of 1533 and 1555 nm have been demultiplexed. An unbalanced Mach-Zehnder interferometer illuminated by a single low-coherence source provides a high-phase-resolution output for each sensor, the outputs of which are sequentially selected in wavelength by a tunable Fabry-Perot interferometer. The minimum detectable strain measured was 90 n 3 / \\radical Hz \\end-radical at 7 Hz for a wavelength of 1535 nm.

Dual-wavelength quantum cascade laser for trace gas spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jágerská, J.; Tuzson, B.; Mangold, M.

2014-10-20

We demonstrate a sequentially operating dual-wavelength quantum cascade laser with electrically separated laser sections, emitting single-mode at 5.25 and 6.25 μm. Based on a single waveguide ridge, this laser represents a considerable asset to optical sensing and trace gas spectroscopy, as it allows probing multiple gas species with spectrally distant absorption features using conventional optical setups without any beam combining optics. The laser capability was demonstrated in simultaneous NO and NO{sub 2} detection, reaching sub-ppb detection limits and selectivity comparable to conventional high-end spectroscopic systems.

A Panel of MicroRNAs as Diagnostic Biomarkers for the Identification of Prostate Cancer.

PubMed

Daniel, Rhonda; Wu, Qianni; Williams, Vernell; Clark, Gene; Guruli, Georgi; Zehner, Zendra

2017-06-16

Prostate cancer is the most common non-cutaneous cancer among men; yet, current diagnostic methods are insufficient, and more reliable diagnostic markers need to be developed. One answer that can bridge this gap may lie in microRNAs. These small RNA molecules impact protein expression at the translational level, regulating important cellular pathways, the dysregulation of which can exert tumorigenic effects contributing to cancer. In this study, high throughput sequencing of small RNAs extracted from blood from 28 prostate cancer patients at initial stages of diagnosis and prior to treatment was used to identify microRNAs that could be utilized as diagnostic biomarkers for prostate cancer compared to 12 healthy controls. In addition, a group of four microRNAs (miR-1468-3p, miR-146a-5p, miR-1538 and miR-197-3p) was identified as normalization standards for subsequent qRT-PCR confirmation. qRT-PCR analysis corroborated microRNA sequencing results for the seven top dysregulated microRNAs. The abundance of four microRNAs (miR-127-3p, miR-204-5p, miR-329-3p and miR-487b-3p) was upregulated in blood, whereas the levels of three microRNAs (miR-32-5p, miR-20a-5p and miR-454-3p) were downregulated. Data analysis of the receiver operating curves for these selected microRNAs exhibited a better correlation with prostate cancer than PSA (prostate-specific antigen), the current gold standard for prostate cancer detection. In summary, a panel of seven microRNAs is proposed, many of which have prostate-specific targets, which may represent a significant improvement over current testing methods.

DigiLens color sequential filtering for microdisplay-based projection applications

NASA Astrophysics Data System (ADS)

Sagan, Stephen F.; Smith, Ronald T.; Popovich, Milan M.

2000-10-01

Application Specific Integrated Filters (ASIFs), based on a unique holographic polymer dispersed liquid crystal (H-PDLC) material system offering high efficiency, fast switching and low power, are being developed for microdisplay based projection applications. A new photonics technology based H-PDLC materials combined with the ability to be electrically switched on and off offers a new approach to color sequential filtering of a white light source for microdisplay-based front and rear projection display applications. Switchable Bragg gratings created in the PDLC are fundamental building blocks. Combined with the well- defined spectral and angular characteristics of Bragg gratings, these selectable filters can provide a large color gamut and a dynamically adjustable white balance. These switchable Bragg gratings can be reflective or transmissive and in each case can be designed to operate in either additive or subtractive mode. The spectral characteristics of filters made from a stack of these Bragg gratings can be configured for a specific lamp spectrum to give high diffractive efficiency over the broad bandwidths required for an illumination system. When it is necessary to reduce the spectral bandwidth, it is possible to use the properties of reflection Bragg holograms to construct very narrow band high efficiency filters. The basic properties and key benefits of ASIFs in projection displays are reviewed.

Development of a sequential workflow based on LC-PRM for the verification of endometrial cancer protein biomarkers in uterine aspirate samples.

PubMed

Martinez-Garcia, Elena; Lesur, Antoine; Devis, Laura; Campos, Alexandre; Cabrera, Silvia; van Oostrum, Jan; Matias-Guiu, Xavier; Gil-Moreno, Antonio; Reventos, Jaume; Colas, Eva; Domon, Bruno

2016-08-16

About 30% of endometrial cancer (EC) patients are diagnosed at an advanced stage of the disease, which is associated with a drastic decrease in the 5-year survival rate. The identification of biomarkers in uterine aspirate samples, which are collected by a minimally invasive procedure, would improve early diagnosis of EC. We present a sequential workflow to select from a list of potential EC biomarkers, those which are the most promising to enter a validation study. After the elimination of confounding contributions by residual blood proteins, 52 potential biomarkers were analyzed in uterine aspirates from 20 EC patients and 18 non-EC controls by a high-resolution accurate mass spectrometer operated in parallel reaction monitoring mode. The differential abundance of 26 biomarkers was observed, and among them ten proteins showed a high sensitivity and specificity (AUC > 0.9). The study demonstrates that uterine aspirates are valuable samples for EC protein biomarkers screening. It also illustrates the importance of a biomarker verification phase to fill the gap between discovery and validation studies and highlights the benefits of high resolution mass spectrometry for this purpose. The proteins verified in this study have an increased likelihood to become a clinical assay after a subsequent validation phase.

Ridge InGaAs/InP multi-quantum-well selective growth in nanoscale trenches on Si (001) substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, S.; Zhou, X.; Li, M.

Metal organic chemical vapor deposition of InGaAs/InP multi-quantum-well in nanoscale V-grooved trenches on Si (001) substrate was studied using the aspect ratio trapping method. A high quality GaAs/InP buffer layer with two convex (111) B facets was selectively grown to promote the highly uniform, single-crystal ridge InP/InGaAs multi-quantum-well structure growth. Material quality was confirmed by transmission electron microscopy and room temperature micro-photoluminescence measurements. This approach shows great promise for the fabrication of photonics devices and nanolasers on Si substrate.

A group sequential adaptive treatment assignment design for proof of concept and dose selection in headache trials.

PubMed

Hall, David B; Meier, Ulrich; Diener, Hans-Cristoph

2005-06-01

The trial objective was to test whether a new mechanism of action would effectively treat migraine headaches and to select a dose range for further investigation. The motivation for a group sequential, adaptive, placebo-controlled trial design was (1) limited information about where across the range of seven doses to focus attention, (2) a need to limit sample size for a complicated inpatient treatment and (3) a desire to reduce exposure of patients to ineffective treatment. A design based on group sequential and up and down designs was developed and operational characteristics were explored by trial simulation. The primary outcome was headache response at 2 h after treatment. Groups of four treated and two placebo patients were assigned to one dose. Adaptive dose selection was based on response rates of 60% seen with other migraine treatments. If more than 60% of treated patients responded, then the next dose was the next lower dose; otherwise, the dose was increased. A stopping rule of at least five groups at the target dose and at least four groups at that dose with more than 60% response was developed to ensure that a selected dose would be statistically significantly (p=0.05) superior to placebo. Simulations indicated good characteristics in terms of control of type 1 error, sufficient power, modest expected sample size and modest bias in estimation. The trial design is attractive for phase 2 clinical trials when response is acute and simple, ideally binary, placebo comparator is required, and patient accrual is relatively slow allowing for the collection and processing of results as a basis for the adaptive assignment of patients to dose groups. The acute migraine trial based on this design was successful in both proof of concept and dose range selection.

Adjuvant sequential chemo and radiotherapy improves the oncological outcome in high risk endometrial cancer

PubMed Central

Signorelli, Mauro; Lissoni, Andrea Alberto; De Ponti, Elena; Grassi, Tommaso; Ponti, Serena

2015-01-01

Objective Evaluation of the impact of sequential chemoradiotherapy in high risk endometrial cancer (EC). Methods Two hundred fifty-four women with stage IB grade 3, II and III EC (2009 FIGO staging), were included in this retrospective study. Results Stage I, II, and III was 24%, 28.7%, and 47.3%, respectively. Grade 3 tumor was 53.2% and 71.3% had deep myometrial invasion. One hundred sixty-five women (65%) underwent pelvic (+/- aortic) lymphadenectomy and 58 (22.8%) had nodal metastases. Ninety-eight women (38.6%) underwent radiotherapy, 59 (23.2%) chemotherapy, 42 (16.5%) sequential chemoradiotherapy, and 55 (21.7%) were only observed. After a median follow-up of 101 months, 78 women (30.7%) relapsed and 91 women (35.8%) died. Sequential chemoradiotherapy improved survival rates in women who did not undergo nodal evaluation (disease-free survival [DFS], p=0.040; overall survival [OS], p=0.024) or pelvic (+/- aortic) lymphadenectomy (DFS, p=0.008; OS, p=0.021). Sequential chemoradiotherapy improved both DFS (p=0.015) and OS (p=0.014) in stage III, while only a trend was found for DFS (p=0.210) and OS (p=0.102) in stage I-II EC. In the multivariate analysis, only age (≤65 years) and sequential chemoradiotherapy were statistically related to the prognosis. Conclusion Sequential chemoradiotherapy improves survival rates in high risk EC compared with chemotherapy or radiotherapy alone, in particular in stage III. PMID:26197768

A DFT study and micro-kinetic analysis of acetylene selective hydrogenation on Pd-doped Cu(111) surfaces

NASA Astrophysics Data System (ADS)

Ma, Ling-Ling; Lv, Cun-Qin; Wang, Gui-Chang

2017-07-01

Semi-hydrogenation of acetylene in a hydrogen-rich stream is an industrially important process. Inspired by the recent experiments that Cu(111) surface doped by a small number of Pd atoms can exhibit excellent catalytic performance toward the dissociation of H2 molecule as well as the high selective hydrogenation of acetylene as compared with pure Cu and Pd metal alone at low-temperature, here we performed systematic first-principles calculations to investigate the corresponding reaction mechanism related to the acetylene hydrogenation processes on single atom alloys (SAAs) and monolayer Pd/Cu(111) (i.e.,1.00 ML Pd/Cu(111)) model catalysts in detail, and to explore the possible factors controlling the high selectivity on SAAs. Our results clearly demonstrate that the SAA catalyst has higher selectivity for the ethylene formation than that of 1.00 ML Pd/Cu(111), and lower activity for the acetylene conversion compared with that of 1.00 ML Pd/Cu(111). The relatively high selectivity on SAA is mainly due to the facile desorption of ethylene and moderate activity in the dissociation of molecular H2. The main factor which lowers the selectivity towards the ethylene formation on 1.00 ML Pd/Cu(111) is that this system has a higher capacity to promote the breaking of Csbnd H/Csbnd C bonds, which leads to the formation of carbonaceous deposits and polymers such as benzene, and thus reduces the selectivity for the ethylene formation. Meanwhile, it was found that the desorption energy of ethylene on these two surfaces was smaller than the energy barrier of further hydrogenation, which results in the absence of ethane on these two systems. Micro-kinetic model analysis provides a further valuable insight into the evidence for the key factors controlling the catalytic activity and selectivity towards the selective hydrogenation of acetylene. Our findings may help people to design a highly selective hydrogenation catalyst by controlling the balance between the H2 dissociation and Csbnd H/Csbnd C bond broken processes, and a good catalyst should be the one with the modest catalytic activity in the activation of molecular H2. At the same time, the present work provides an extremely significant mechanism of acetylene trimerization to form benzene and carbon formation.

Sequential algorithm analysis to facilitate selective biliary access for difficult biliary cannulation in ERCP: a prospective clinical study.

PubMed

Lee, Tae Hoon; Hwang, Soon Oh; Choi, Hyun Jong; Jung, Yunho; Cha, Sang Woo; Chung, Il-Kwun; Moon, Jong Ho; Cho, Young Deok; Park, Sang-Heum; Kim, Sun-Joo

2014-02-17

Numerous clinical trials to improve the success rate of biliary access in difficult biliary cannulation (DBC) during ERCP have been reported. However, standard guidelines or sequential protocol analysis according to different methods are limited in place. We planned to investigate a sequential protocol to facilitate selective biliary access for DBC during ERCP. This prospective clinical study enrolled 711 patients with naïve papillae at a tertiary referral center. If wire-guided cannulation was deemed to have failed due to the DBC criteria, then according to the cannulation algorithm early precut fistulotomy (EPF; cannulation time > 5 min, papillary contacts > 5 times, or hook-nose-shaped papilla), double-guidewire cannulation (DGC; unintentional pancreatic duct cannulation ≥ 3 times), and precut after placement of a pancreatic stent (PPS; if DGC was difficult or failed) were performed sequentially. The main outcome measurements were the technical success, procedure outcomes, and complications. Initially, a total of 140 (19.7%) patients with DBC underwent EPF (n = 71) and DGC (n = 69). Then, in DGC group 36 patients switched to PPS due to difficulty criteria. The successful biliary cannulation rate was 97.1% (136/140; 94.4% [67/71] with EPF, 47.8% [33/69] with DGC, and 100% [36/36] with PPS; P < 0.001). The mean successful cannulation time (standard deviation) was 559.4 (412.8) seconds in EPF, 314.8 (65.2) seconds in DGC, and 706.0 (469.4) seconds in PPS (P < 0.05). The DGC group had a relatively low successful cannulation rate (47.8%) but had a shorter cannulation time compared to the other groups due to early switching to the PPS method in difficult or failed DGC. Post-ERCP pancreatitis developed in 14 (10%) patients (9 mild, 1 moderate), which did not differ significantly among the groups (P = 0.870) or compared with the conventional group (P = 0.125). Based on the sequential protocol analysis, EPF, DGC, and PPS may be safe and feasible for DBC. The use of EPF in selected DBC criteria, DGC in unintentional pancreatic duct cannulations, and PPS in failed or difficult DGC may facilitate successful biliary cannulation.

Fabrication of AlN/BN bishell hollow nanofibers by electrospinning and atomic layer deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haider, Ali; Kayaci, Fatma; Uyar, Tamer

2014-09-01

Aluminum nitride (AlN)/boron nitride (BN) bishell hollow nanofibers (HNFs) have been fabricated by successive atomic layer deposition (ALD) of AlN and sequential chemical vapor deposition (CVD) of BN on electrospun polymeric nanofibrous template. A four-step fabrication process was utilized: (i) fabrication of polymeric (nylon 6,6) nanofibers via electrospinning, (ii) hollow cathode plasma-assisted ALD of AlN at 100 °C onto electrospun polymeric nanofibers, (iii) calcination at 500 °C for 2 h in order to remove the polymeric template, and (iv) sequential CVD growth of BN at 450 °C. AlN/BN HNFs have been characterized for their chemical composition, surface morphology, crystal structure, and internal nanostructuremore » using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and selected area electron diffraction. Measurements confirmed the presence of crystalline hexagonal BN and AlN within the three dimensional (3D) network of bishell HNFs with relatively low impurity content. In contrast to the smooth surface of the inner AlN layer, outer BN coating showed a highly rough 3D morphology in the form of BN nano-needle crystallites. It is shown that the combination of electrospinning and plasma-assisted low-temperature ALD/CVD can produce highly controlled multi-layered bishell nitride ceramic hollow nanostructures. While electrospinning enables easy fabrication of nanofibrous template, self-limiting reactions of plasma-assisted ALD and sequential CVD provide control over the wall thicknesses of AlN and BN layers with sub-nanometer accuracy.« less

Unravelling the effects of gene flow and selection in highly connected populations of the silver-lip pearl oyster (Pinctada maxima).

PubMed

Nayfa, Maria G; Zenger, Kyall R

2016-08-01

Many marine organisms often display weak levels of population genetic structuring as a result of both environmental characteristics (e.g., ocean currents) and life history traits (e.g., widely dispersed planktonic larval stages) maintaining high levels of gene flow. This can lead to the assumption that these organisms can be managed as a single stock based on high levels of population connectivity. However, this neglects to account for other micro-evolutionary forces such as selection, which also shape these populations. This study utilizes 1130 genome-wide SNP loci to unravel the effects of gene flow and selection shaping three highly connected populations of the silver-lip pearl oyster (Pinctada maxima) in the ecologically and economically important Indo-Pacific region (Aru, Bali, and West Papua). Twenty-two loci under directional selection were identified amongst the populations, providing further supporting evidence of strong local adaptation (i.e., G×E effects) among populations in this region. Global Fst values for directional outliers (0.348) were up to eight times greater than for neutral markers (0.043). Pairwise Fst comparisons between Aru and Bali revealed the largest directional differences (0.488), while Bali and West Papua had the least (0.062). Unrooted neighbour-joining (NJ) distance trees and genetic diversity indices of directional outliers revealed that individuals from Bali and West Papua had reduced allelic variation (MAFavg=0.144, Ho=0.238 and MAFavg=0.232, Ho=0.369, respectively) compared to Aru (MAFavg=0.292, Ho=0.412). This indicates that directional selection is most likely acting upon genetic variation within the Bali and West Papua populations. NJ distance trees, discriminant analysis of principal components, and Fst analyses of directional outliers revealed two divergent groups ("Bali/West Papua"; "Aru") that had previously gone unrecognized. This study not only illustrates that relatively strong local adaptive forces are occurring despite high gene flow, but identifies the populations that are most likely experiencing selection. Additionally, this study highlights the need to understand all micro-evolutionary forces acting on populations when resolving stock structure. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

A strategy for clone selection under different production conditions.

PubMed

Legmann, Rachel; Benoit, Brian; Fedechko, Ronald W; Deppeler, Cynthia L; Srinivasan, Sriram; Robins, Russell H; McCormick, Ellen L; Ferrick, David A; Rodgers, Seth T; Russo, A Peter

2011-01-01

Top performing clones have failed at the manufacturing scale while the true best performer may have been rejected early in the screening process. Therefore, the ability to screen multiple clones in complex fed-batch processes using multiple process variations can be used to assess robustness and to identify critical factors. This dynamic ranking of clones' strategy requires the execution of many parallel experiments than traditional approaches. Therefore, this approach is best suited for micro-bioreactor models which can perform hundreds of experiments quickly and efficiently. In this study, a fully monitored and controlled small scale platform was used to screen eight CHO clones producing a recombinant monoclonal antibody across several process variations, including different feeding strategies, temperature shifts and pH control profiles. The first screen utilized 240 micro-bioreactors were run for two weeks for this assessment of the scale-down model as a high-throughput tool for clone evaluation. The richness of the outcome data enable to clearly identify the best and worst clone as well as process in term of maximum monoclonal antibody titer. The follow-up comparison study utilized 180 micro-bioreactors in a full factorial design and a subset of 12 clone/process combinations was selected to be run parallel in duplicate shake flasks. Good correlation between the micro-bioreactor predictions and those made in shake flasks with a Pearson correlation value of 0.94. The results also demonstrate that this micro-scale system can perform clone screening and process optimization for gaining significant titer improvements simultaneously. This dynamic ranking strategy can support better choices of production clones. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Micro-electromechanical sensors in the analytical field.

PubMed

Zougagh, Mohammed; Ríos, Angel

2009-07-01

Micro- and nano-electromechanical systems (MEMS and NEMS) for use as sensors represent one of the most exciting new fields in analytical chemistry today. These systems are advantageous over currently available non-miniaturized sensors, such as quartz crystal microbalances, thickness shear mode resonators, and flexural plate wave oscillators, because of their high sensitivity, low cost and easy integration into automated systems. In this article, we present and discuss the evolution in the use of MEMS and NEMS, which are basically cantilever-type sensors, as good analytical tools for a wide variety of applications. We discuss the analytical features and the practical potential of micro(nano)-cantilever sensors, which combine the synergetic advantages of selectivity, provided by their functionalization, and the high sensitivity, which is attributed largely to the extremely small size of the sensing element. An insight is given into the different types of functionalization and detection strategies and a critical discussion is presented on the existing state of the art concerning the applications reported for mechanical microsensors. New developments and the possibilities for routine work in the near future are also covered.

EVALUATION OF HYBRID POPLAR TREE TOLERANCE TO IRRIGATION WITH HIGH SALINITY AND BORON WATERS UNDER MICRO-PLOT CONDITIONS

USDA-ARS?s Scientific Manuscript database

The concept of reusing salt-laden drainage water in agricultural systems was developed as part of the integrated on-farm drainage management system. The successful adoption of a practical water reuse strategy in Central California requires the selection of salt and boron tolerant crops for use with ...

Study of Laser Drilled Hole Quality of Yttria Stabilized Zirconia

NASA Astrophysics Data System (ADS)

Saini, Surendra K.; Dubey, Avanish K.; Pant, Piyush; Upadhyay, B. N.; Choubey, A.

2017-09-01

The Yttria Stabilized Zirconia ceramic is extensively used in aerospace, automotives, medical and microelectronics industries. These applications demand manufacturing of different macro and micro features with close tolerances in this material. To make miniature holes with accurate dimensions in advanced ceramics such as Yttria Stabilized Zirconia is very difficult due to its tailored attributes such as high toughness, hardness, strength, resistance to wear, corrosion and temperature. Due to inherent characteristics of laser drilling, researchers are working to fulfill the requirement of creation of micro holes in advanced ceramics. The present research investigates the laser drilling of 2 mm thick Yttria Stabilized Zirconia with the aim to achieve good micro holes with reduced geometrical inaccuracies and improved hole quality. The results show that multiple quality response comprising hole circularity, hole taper and recast layer thickness has been improved at optimally selected process parameters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yong; State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080; Zhu, Qingshan, E-mail: qszhu@home.ipe.ac.cn

{beta}-Ni(OH){sub 2} hierarchical micro-flowers, hierarchical hollow microspheres and nanosheets were synthesized via a facile, single-step and selected-control hydrothermal method. Both hierarchical micro-flowers and hierarchical hollow microspheres were built from two-dimensional nanosheets with thickness of 50-100 nm. The as-obtained products were characterized by Brunauer-Emmett-Teller (BET) surface area analysis, X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM). It was observed that marked morphological changes in {beta}-Ni(OH){sub 2} depended on the initial concentrations of Ni{sup 2+} ions and glycine. A possible growth mechanism was proposed based on experimental results. In addition, the effect of morphology on the electrochemical properties wasmore » also investigated. Both hierarchical micro-flowers and hierarchical hollow microspheres exhibited enhanced specific capacity and high-rate discharge ability as compared with pure Ni(OH){sub 2} nanosheets. Investigations confirmed that hierarchical structures had a pronounced influence upon the electrochemical performance of nickel hydroxide.« less

Geochemical Transformation of Cadmium (Cd) from Creek to Paddy Fields in W Thailand

NASA Astrophysics Data System (ADS)

Kosolsaksakul, Peerapat; Graham, Margaret; Farmer, John

2013-04-01

Extensive Cd contamination of paddy soils in Tak Province, western Thailand, a consequence of Zn mining activities, was first established in 2005 and medical studies showed that the health of local communities was being impaired. Mae Tao, Tak Province, comprising many paddy fields and irrigation canals, has been selected for this study of the geochemical transformation of Cd from the contamination source in the mountainous region to the east of the study site through the community irrigation system to the paddy soils. The aim of this research is to (i) investigate the geochemical transformation of Cd as it is transported from the main irrigation creek through the canals and to the paddy fields, (ii) assess the availability of Cd to rice plants, which may be affected by both chemical and physical factors, and (iii) trial some practical treatments to minimise Cd concentrations in rice grains. Soils, irrigation canal sediments and water samples were collected during the dry season and at the onset of the rainy season. Rice samples were collected at harvesting time and samples of soil fertiliser were also obtained. Water samples were filtered, ultrafiltered and analysed by ICP-MS whilst sub-samples of dried, ground soils and sediments were first subjected to micro-wave assisted acid digestion (modified US EPA method 3052). XRD and SEM-EDX methods were used for mineralogical characterisation and selective chemical extractions have assisted in the characterisation of solid phase Cd associations. Soil Cd concentrations were in the range 2.5-87.6 µg g-1, with higher values being obtained for fields furthest from the main creek. Although current irrigation water Cd inputs are low (mean 1.9 μg L-1; flood period), high loads of suspended particles still contribute additional Cd (4.2-9.8 µg L-1) to the paddy fields. For bioavailability assessment by a 3-step BCR sequential extraction, 70-90% Cd was in the exchangeable; HOAc-extractable fraction. That indicated that most of the Cd was in water soluble, exchangeable and carbonate-bound forms. For the fields with highest Cd concentration, SEM-EDX analysis identified two forms of Cd, i.e. Cd-Clay and Cd-CaCO3, in good agreement with the sequential extraction data. The predominance of easily extractable forms in the paddy field soils suggests that Cd may be readily absorbed by the rice plants. After harvesting, the Cd concentration in rice grains ranged from 0.05-4.0 µg g-1 and the concentration trends across the group of 18 fields matched well with the soil Cd data. Rice from nine out of the 18 fields contained Cd at greater than the safe level of 0.4 µg g-1.

Sequential infection with common pathogens promotes human-like immune gene expression and altered vaccine response

PubMed Central

Reese, Tiffany A.; Bi, Kevin; Kambal, Amal; Filali-Mouhim, Ali; Beura, Lalit K.; Bürger, Matheus C.; Pulendran, Bali; Sekaly, Rafick; Jameson, Stephen C.; Masopust, David; Haining, W. Nicholas; Virgin, Herbert W.

2016-01-01

Summary Immune responses differ between laboratory mice and humans. Chronic infection with viruses and parasites are common in humans, but are absent in laboratory mice, and thus represent potential contributors to inter-species differences in immunity. To test this, we sequentially infected laboratory mice with herpesviruses, influenza, and an intestinal helminth, and compared their blood immune signatures to mock-infected mice before and after vaccination against Yellow Fever Virus (YFV-17D). Sequential infection altered pre- and post-vaccination gene expression, cytokines, and antibodies in blood. Sequential pathogen exposure induced gene signatures that recapitulated those seen in blood from pet store-raised versus laboratory mice, and adult versus cord blood in humans. Therefore basal and vaccine-induced murine immune responses are altered by infection with agents common outside of barrier facilities. This raises the possibility that we can improve mouse models of vaccination and immunity by selective microbial exposure of laboratory animals to mimic that of humans. PMID:27107939

Three parameters optimizing closed-loop control in sequential segmental neuromuscular stimulation.

PubMed

Zonnevijlle, E D; Somia, N N; Perez Abadia, G; Stremel, R W; Maldonado, C J; Werker, P M; Kon, M; Barker, J H

1999-05-01

In conventional dynamic myoplasties, the force generation is poorly controlled. This causes unnecessary fatigue of the transposed/transplanted electrically stimulated muscles and causes damage to the involved tissues. We introduced sequential segmental neuromuscular stimulation (SSNS) to reduce muscle fatigue by allowing part of the muscle to rest periodically while the other parts work. Despite this improvement, we hypothesize that fatigue could be further reduced in some applications of dynamic myoplasty if the muscles were made to contract according to need. The first necessary step is to gain appropriate control over the contractile activity of the dynamic myoplasty. Therefore, closed-loop control was tested on a sequentially stimulated neosphincter to strive for the best possible control over the amount of generated pressure. A selection of parameters was validated for optimizing control. We concluded that the frequency of corrections, the threshold for corrections, and the transition time are meaningful parameters in the controlling algorithm of the closed-loop control in a sequentially stimulated myoplasty.

Blocking for Sequential Political Experiments

PubMed Central

Moore, Sally A.

2013-01-01

In typical political experiments, researchers randomize a set of households, precincts, or individuals to treatments all at once, and characteristics of all units are known at the time of randomization. However, in many other experiments, subjects “trickle in” to be randomized to treatment conditions, usually via complete randomization. To take advantage of the rich background data that researchers often have (but underutilize) in these experiments, we develop methods that use continuous covariates to assign treatments sequentially. We build on biased coin and minimization procedures for discrete covariates and demonstrate that our methods outperform complete randomization, producing better covariate balance in simulated data. We then describe how we selected and deployed a sequential blocking method in a clinical trial and demonstrate the advantages of our having done so. Further, we show how that method would have performed in two larger sequential political trials. Finally, we compare causal effect estimates from differences in means, augmented inverse propensity weighted estimators, and randomization test inversion. PMID:24143061

Microfluidic devices to enrich and isolate circulating tumor cells

PubMed Central

Myung, J. H.; Hong, S.

2015-01-01

Given the potential clinical impact of circulating tumor cells (CTCs) in blood as a clinical biomarker for diagnosis and prognosis of various cancers, a myriad of detection methods for CTCs have been recently introduced. Among those, a series of microfluidic devices are particularly promising as these uniquely offer micro-scale analytical systems that are highlighted by low consumption of samples and reagents, high flexibility to accommodate other cutting-edge technologies, precise and well-defined flow behaviors, and automation capability, presenting significant advantages over the conventional larger scale systems. In this review, we highlight the advantages of microfluidic devices and their translational potential into CTC detection methods, categorized by miniaturization of bench-top analytical instruments, integration capability with nanotechnologies, and in situ or sequential analysis of captured CTCs. This review provides a comprehensive overview of recent advances in the CTC detection achieved through application of microfluidic devices and their challenges that these promising technologies must overcome to be clinically impactful. PMID:26549749

Controllable lasing performance in solution-processed organic-inorganic hybrid perovskites.

PubMed

Kao, Tsung Sheng; Chou, Yu-Hsun; Hong, Kuo-Bin; Huang, Jiong-Fu; Chou, Chun-Hsien; Kuo, Hao-Chung; Chen, Fang-Chung; Lu, Tien-Chang

2016-11-03

Solution-processed organic-inorganic perovskites are fascinating due to their remarkable photo-conversion efficiency and great potential in the cost-effective, versatile and large-scale manufacturing of optoelectronic devices. In this paper, we demonstrate that the perovskite nanocrystal sizes can be simply controlled by manipulating the precursor solution concentrations in a two-step sequential deposition process, thus achieving the feasible tunability of excitonic properties and lasing performance in hybrid metal-halide perovskites. The lasing threshold is at around 230 μJ cm -2 in this solution-processed organic-inorganic lead-halide material, which is comparable to the colloidal quantum dot lasers. The efficient stimulated emission originates from the multiple random scattering provided by the micro-meter scale rugged morphology and polycrystalline grain boundaries. Thus the excitonic properties in perovskites exhibit high correlation with the formed morphology of the perovskite nanocrystals. Compared to the conventional lasers normally serving as a coherent light source, the perovskite random lasers are promising in making low-cost thin-film lasing devices for flexible and speckle-free imaging applications.

Computers and Reading: 1984-1989. Selections from "Micro Missive," the Newsletter of MicroSIG, The Special Interest Group for Microcomputers in Reading of the International Reading Association.

ERIC Educational Resources Information Center

Balajthy, Ernest

This publication is a collection of eight articles and ten software reviews written by the author for "Micro Missive" since 1984. "Micro Missive" is a quarterly newsletter that has regularly informed International Reading Association members of new developments in computer-based instruction and reading/language arts through articles, software…

Evidence that tachykinin NK1 and NK2 receptors mediate non-adrenergic non-cholinergic excitation and contraction in the circular muscle of guinea-pig duodenum.

PubMed Central

Zagorodnyuk, V.; Santicioli, P.; Maggi, C. A.; Giachetti, A.

1995-01-01

1. In the presence of atropine (1 microM), guanethidine (3 microM), indomethacin (3 microM), apamin (0.1 microM) and L-nitroarginine (L-NOARG, 30 microM), electrical field simulation (EFS) produced a nonadrenergic, noncholinergic (NANC) excitatory junctional potential (e.j.p.), action potentials and contraction of the circular muscle of the guinea-pig proximal duodenum, recorded by the single sucrose gap technique. 2. The selective tachykinin (TK) NK1 receptor antagonist, GR 82,334 (30 nM-3 microM) produced a concentration-dependent inhibition of the EFS-evoked NANC e.j.p. and contraction. Similarly, the selective NK2 receptor antagonists, MEN 10,627 (30 nM-3 microM) and GR 94,800 (100 nM-10 microM), both produced a concentration-dependent inhibition of the EFS-evoked NANC e.j.p. and contraction. GR 82,334 inhibited the electrical and mechanical NANC responses to EFS in an almost parallel manner, while MEN 10,627 and GR 94,800 were more effective in inhibiting the mechanical than the electrical response to EFS. 3. Activation of the NK1 or NK2 receptor by the selective agonists, [Sar9]substance P (SP) sulphone and [beta Ala8]neurokinin A (NKA) (4-10), respectively (0.3 microM each), produced depolarization, action potentials and contractions. GR 82,334 selectively inhibited the responses to [Sar9]SP sulphone, without affecting the responses to [beta Ala8]NKA (4-10). MEN 10,627 and GR 94,800 inhibited or abolished the responses to [beta Ala8]NKA (4-10), without affecting the responses to [Sar9]SP sulphone. 4. Nifedipine (1 microM) abolished the action potentials and contraction produced either by EFS or by the TK receptor agonists [Sar9]SP sulphone or [beta Ala8]NKA (4-10). 5. In the presence of nifedipine, the NANC e.j.p. produced by EFS was biphasic: in the majority of strips tested (21 out of 29) an early fast phase of depolarization was followed by a second slow component. The combined administration of GR 82,334 and GR 94,800 (3 microM each) reduced both components, the slow phase being inhibited to a greater extent than the fast phase. 6. The P2 purinoreceptor antagonist, suramin (100 microM) reduced the fast phase of the e.j.p. produced by EFS in the presence of nifedipine, without affecting the slow phase. The combined administration of suramin, GR 82,334 and GR 94,800 produced a nearly complete blockade of the e.j.p. produced by EFS in the presence of nifedipine. 7. When tested in the absence of apamin and L-NOARG, EFS induced a NANC inhibitory junction potential (i.j.p.) followed by an e.j.p., and the selective P2Y receptor agonist, adenosine-5'-O-(2-thiodiphosphate) (ADP beta S, 10 microM), produced membrane hyperpolarization.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7545517

Unsteady, one-dimensional gas dynamics computations using a TVD type sequential solver

NASA Technical Reports Server (NTRS)

Thakur, Siddharth; Shyy, Wei

1992-01-01

The efficacy of high resolution convection schemes to resolve sharp gradient in unsteady, 1D flows is examined using the TVD concept based on a sequential solution algorithm. Two unsteady flow problems are considered which include the problem involving the interaction of the various waves in a shock tube with closed reflecting ends and the problem involving the unsteady gas dynamics in a tube with closed ends subject to an initial pressure perturbation. It is concluded that high accuracy convection schemes in a sequential solution framework are capable of resolving discontinuities in unsteady flows involving complex gas dynamics. However, a sufficient amount of dissipation is required to suppress oscillations near discontinuities in the sequential approach, which leads to smearing of the solution profiles.

Persistence of evolutionary memory: primordial six-transmembrane helical domain mu opiate receptors selectively linked to endogenous morphine signaling.

PubMed

Kream, Richard M; Sheehan, Melinda; Cadet, Patrick; Mantione, Kirk J; Zhu, Wei; Casares, Federico; Stefano, George B

2007-12-01

Biochemical, molecular and pharmacological evidence for two unique six-transmembrane helical (TMH) domain opiate receptors expressed from the micro opioid receptor (MOR) gene have been shown. Designated micro3 and micro4 receptors, both protein species are Class A rhodopsin-like members of the superfamily of G-protein coupled receptors but are selectively tailored to mediate the cellular regulatory effects of endogenous morphine and related morphinan alkaloids via stimulation of nitric oxide (NO) production and release. Both micro3 and micro4 receptors lack an amino acid sequence of approximately 90 amino acids that constitute the extracellular N-terminal and TMH1 domains and part of the first intracellular loop of the micro1 receptor, but retain the empirically defined ligand binding pocket distributed across conserved TMH2, TMH3, and TMH7 domains of the micro1 sequence. Additionally, the receptor proteins are terminated by unique intracellular C-terminal amino acid sequences that serve as putative coupling or docking domains required for constitutive NO synthase activation. Because the recognition profile of micro3 and micro4 receptors is restricted to rigid benzylisoquinoline alkaloids typified by morphine and its extended family of chemical congeners, it is hypothesized that conformational stabilization provided by interaction of extended extracellular N-terminal protein domains and the extracellular loops is required for binding of endogenous opioid peptides as well as synthetic flexible opiate alkaloids.

Syngas generation from n-butane with an integrated MEMS assembly for gas processing in micro-solid oxide fuel cell systems.

PubMed

Bieberle-Hütter, A; Santis-Alvarez, A J; Jiang, B; Heeb, P; Maeder, T; Nabavi, M; Poulikakos, D; Niedermann, P; Dommann, A; Muralt, P; Bernard, A; Gauckler, L J

2012-11-21

An integrated system of a microreformer and a carrier allowing for syngas generation from liquefied petroleum gas (LPG) for micro-SOFC application is discussed. The microreformer with an overall size of 12.7 mm × 12.7 mm × 1.9 mm is fabricated with micro-electro-mechanical system (MEMS) technologies. As a catalyst, a special foam-like material made from ceria-zirconia nanoparticles doped with rhodium is used to fill the reformer cavity of 58.5 mm(3). The microreformer is fixed onto a microfabricated structure with built-in fluidic channels and integrated heaters, the so-called functional carrier. It allows for thermal decoupling of the cold inlet gas and the hot fuel processing zone. Two methods for heating the microreformer are compared in this study: a) heating in an external furnace and b) heating with the two built-in heaters on the functional carrier. With both methods, high butane conversion rates of 74%-85% are obtained at around 550 °C. In addition, high hydrogen and carbon monoxide yields and selectivities are achieved. The results confirm those from classical lab reformers built without MEMS technology (N. Hotz et al., Chem. Eng. Sci., 2008, 63, 5193; N. Hotz et al., Appl. Catal., B, 2007, 73, 336). The material combinations and processing techniques enable syngas production with the present MEMS based microreformer with high performance for temperatures up to 700 °C. The functional carrier is the basis for a new platform, which can integrate the micro-SOFC membranes and the gas processing unit as subsystem of an entire micro-SOFC system.

Optimizing trial design in pharmacogenetics research: comparing a fixed parallel group, group sequential, and adaptive selection design on sample size requirements.

PubMed

Boessen, Ruud; van der Baan, Frederieke; Groenwold, Rolf; Egberts, Antoine; Klungel, Olaf; Grobbee, Diederick; Knol, Mirjam; Roes, Kit

2013-01-01

Two-stage clinical trial designs may be efficient in pharmacogenetics research when there is some but inconclusive evidence of effect modification by a genomic marker. Two-stage designs allow to stop early for efficacy or futility and can offer the additional opportunity to enrich the study population to a specific patient subgroup after an interim analysis. This study compared sample size requirements for fixed parallel group, group sequential, and adaptive selection designs with equal overall power and control of the family-wise type I error rate. The designs were evaluated across scenarios that defined the effect sizes in the marker positive and marker negative subgroups and the prevalence of marker positive patients in the overall study population. Effect sizes were chosen to reflect realistic planning scenarios, where at least some effect is present in the marker negative subgroup. In addition, scenarios were considered in which the assumed 'true' subgroup effects (i.e., the postulated effects) differed from those hypothesized at the planning stage. As expected, both two-stage designs generally required fewer patients than a fixed parallel group design, and the advantage increased as the difference between subgroups increased. The adaptive selection design added little further reduction in sample size, as compared with the group sequential design, when the postulated effect sizes were equal to those hypothesized at the planning stage. However, when the postulated effects deviated strongly in favor of enrichment, the comparative advantage of the adaptive selection design increased, which precisely reflects the adaptive nature of the design. Copyright © 2013 John Wiley & Sons, Ltd.

Optical fiber micro-displacement sensor using a refractive index modulation window-assisted reflection fiber taper

NASA Astrophysics Data System (ADS)

Bao, Weijia; Qiao, Xueguang; Yin, Xunli; Rong, Qiangzhou; Wang, Ruohui; Yang, Hangzhou

2017-12-01

We demonstrate a compact fiber-optic quasi-Michelson interferometer (QMI) for micro-displacement measurement. The sensor comprises a micro-structure of a reflection taper tip containing a refractive index modification (RIM) as a coupling window over the interface between core and cladding of the fiber. Femtosecond laser-based direct inscription technique is used to achieve this window inscription and to induce large refractive index change. The RIM acts as a window for the strong coupling and recoupling of core-to-cladding modes. As the core and cladding modes are reflected at the taper tip and coupled back to lead-in fiber, a well-defined interference spectrum is achieved. The spectral intensity exhibits a high micro-bending sensitivity of 4 . 94 dB / μm because of the sensitivity to bending of recoupled intensity of cladding modes. In contrast, the spectral wavelength is insensitive to bending but linearly responds to temperature. The simultaneous measurements, including power-referenced for displacement and wavelength-referenced for temperature, were achieved by selective interference dip monitoring.

Integrated Microfluidic System for Size-Based Selection and Trapping of Giant Vesicles.

PubMed

Kazayama, Yuki; Teshima, Tetsuhiko; Osaki, Toshihisa; Takeuchi, Shoji; Toyota, Taro

2016-01-19

Vesicles composed of phospholipids (liposomes) have attracted interest as artificial cell models and have been widely studied to explore lipid-lipid and lipid-protein interactions. However, the size dispersity of liposomes prepared by conventional methods was a major problem that inhibited their use in high-throughput analyses based on monodisperse liposomes. In this study, we developed an integrative microfluidic device that enables both the size-based selection and trapping of liposomes. This device consists of hydrodynamic selection and trapping channels in series, which made it possible to successfully produce an array of more than 60 monodisperse liposomes from a polydisperse liposome suspension with a narrow size distribution (the coefficient of variation was less than 12%). We successfully observed a size-dependent response of the liposomes to sequential osmotic stimuli, which had not clarified so far, by using this device. Our device will be a powerful tool to facilitate the statistical analysis of liposome dynamics.

Sequential and selective localized optical heating in water via on-chip dielectric nanopatterning.

PubMed

Morsy, Ahmed M; Biswas, Roshni; Povinelli, Michelle L

2017-07-24

We study the use of nanopatterned silicon membranes to obtain optically-induced heating in water. We show that by varying the detuning between an absorptive optical resonance of the patterned membrane and an illumination laser, both the magnitude and response time of the temperature rise can be controlled. This allows for either sequential or selective heating of different patterned areas on chip. We obtain a steady-state temperature of approximately 100 °C for a 805.5nm CW laser power density of 66 µW/μm 2 and observe microbubble formation. The ability to spatially and temporally control temperature on the microscale should enable the study of heat-induced effects in a variety of chemical and biological lab-on-chip applications.

Target-responsive DNA/RNA nanomaterials for microRNA sensing and inhibition: the jack-of-all-trades in cancer nanotheranostics?

PubMed

Conde, João; Edelman, Elazer R; Artzi, Natalie

2015-01-01

microRNAs (miRNAs) show high potential for cancer treatment, however one of the most significant bottlenecks in enabling miRNA effect is the need for an efficient vehicle capable of selective targeting to tumor cells without disrupting normal cells. Even more challenging is the ability to detect and silence multiple targets simultaneously with high sensitivity while precluding resistance to the therapeutic agents. Focusing on the pervasive role of miRNAs, herein we review the multiple nanomaterial-based systems that encapsulate DNA/RNA for miRNA sensing and inhibition in cancer therapy. Understanding the potential of miRNA detection and silencing while overcoming existing limitations will be critical to the optimization and clinical utilization of this technology. Copyright © 2014 Elsevier B.V. All rights reserved.

Minimalist-design, high-functionality, micro-ring resonator-based optical filter with narrow linewidth and low group delay using Looped Back Over- and Under-coupled Resonator (LOBOUR)

NASA Astrophysics Data System (ADS)

Ye, Bo; Dingel, Benjamin B.; Cui, Weili

2013-01-01

We present a minimalist design but high functionality micro-ring resonator based optical filter with narrow linewidth and low group delay using a novel design we called LOBOUR for LOoped-Back Over- and Under- Coupled Resonator (LOBOUR). The characteristics of both narrow linewidth and low group delay (low chromatic dispersion) generally do not come together especially when using a single ring resonator. The Cascaded Over- and Under-Coupled Resonator (COUR) design was able to achieve this goal but introduced many practical fabrication issues. Here, we present an alternative design to COUR which uses only one ring resonator and without fabrication and manufacturing issues. It can achieve 50 dB extinction ratio and tens of ps performance. We also present important parameter selection mapping for LOBOUR.

Simultaneous determination of the quantity and isotopic ratios of uranium in individual micro-particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS).

PubMed

Park, Jong-Ho; Choi, Eun-Ju

2016-11-01

A method to determine the quantity and isotopic ratios of uranium in individual micro-particles simultaneously by isotope dilution thermal ionization mass spectrometry (ID-TIMS) has been developed. This method consists of sequential sample and spike loading, ID-TIMS for isotopic measurement, and application of a series of mathematical procedures to remove the contribution of uranium in the spike. The homogeneity of evaporation and ionization of uranium content was confirmed by the consistent ratio of n((233)U)/n((238)U) determined by TIMS measurements. Verification of the method was performed using U030 solution droplets and U030 particles. Good agreements of resulting uranium quantity, n((235)U)/n((238)U), and n((236)U)/n((238)U) with the estimated or certified values showed the validity of this newly developed method for particle analysis when simultaneous determination of the quantity and isotopic ratios of uranium is required. Copyright © 2016 Elsevier B.V. All rights reserved.

Sequential Tool Use in Great Apes

PubMed Central

Martin-Ordas, Gema; Schumacher, Lena; Call, Josep

2012-01-01

Sequential tool use is defined as using a tool to obtain another non-food object which subsequently itself will serve as a tool to act upon a further (sub)goal. Previous studies have shown that birds and great apes succeed in such tasks. However, the inclusion of a training phase for each of the sequential steps and the low cost associated with retrieving the longest tools limits the scope of the conclusions. The goal of the experiments presented here was, first to replicate a previous study on sequential tool use conducted on New Caledonian crows and, second, extend this work by increasing the cost of retrieving a tool in order to test tool selectivity of apes. In Experiment 1, we presented chimpanzees, orangutans and bonobos with an out-of-reach reward, two tools that were available but too short to reach the food and four out-of-reach tools differing in functionality. Similar to crows, apes spontaneously used up to 3 tools in sequence to get the reward and also showed a strong preference for the longest out-of reach tool independently of the distance of the food. In Experiment 2, we increased the cost of reaching for the longest out-of reach tool. Now apes used up to 5 tools in sequence to get the reward and became more selective in their choice of the longest tool as the costs of its retrieval increased. The findings of the studies presented here contribute to the growing body of comparative research on tool use. PMID:23300592

Sequential and Simultaneous Processing Abilities of High-Functioning Autistic and Language-Impaired Children.

ERIC Educational Resources Information Center

Allen, Mark H.; And Others

1991-01-01

This study found that a group of 20 children (ages 6-12) with autism and a group of 20 children with developmental receptive language disorder both manifested a relative sequential processing deficit. The groups did not differ significantly on overall sequential and simultaneous processing capabilities relative to their degree of language…

Indoor transformer stations as predictors of residential ELF magnetic field exposure.

PubMed

Ilonen, K; Markkanen, A; Mezei, G; Juutilainen, Jukka

2008-04-01

Transformer stations in apartment buildings may offer a possibility to conduct epidemiological studies that involve high exposure to extremely low frequency magnetic fields (MF), avoid selection bias and minimize confounding factors. To validate exposure assessment based on transformer stations, measurements were performed in thirty buildings in three Finnish cities. In each building, spot measurements in all rooms and a 24-h recording in a bedroom were performed in one apartment above a transformer station (AAT), in one first floor (FF) reference apartment, and one reference apartment on upper floors (UF). The apartment mean of spot measurements was 0.62 microT in the AATs, 0.21 microT in the FF and 0.11 microT in the UF reference apartments The 24-h apartment mean (estimated from the spot measurements and the bedroom 24-h recording) was 0.2 microT or higher in 29 (97%) AATs, in 7 (25%) FF and in 3 (10 %) UF reference apartments. The corresponding numbers for the 0.4 microT cut-off point were 19 (63%), 4 (14%), and 1 (3.3%). The higher MF level in the FF reference apartments indicates that they should not be considered "unexposed" in epidemiological studies. If such apartments are excluded, a transformer station under the floor predicts 24-h apartment mean MF with a sensitivity of 0.41 (or 0.58) and a specificity of 0.997 (or 0.97), depending on the MF cut-off point (0.2 or 0.4 microT). The results indicate that apartments can be reliably classified as high and low MF field categories based on the known location of transformer stations. (c) 2007 Wiley-Liss, Inc.

Deep UV Narrow-Band Photodetector Based on Ion Beam Synthesized Indium Oxide Quantum Dots in Al2O3 Matrix.

PubMed

Rajamani, Saravanan; Arora, Kanika; Konakov, Anton; Belov, Alexey; Korolev, Dmitry; Nikolskaya, Alyona; Mikhaylov, Alexey N; Surodin, Sergey; Kryukov, Ruslan; Nikolichev, Dmitri; Sushkov, Artem; Pavlov, Dmitry; Tetelbaum, David; Kumar, Mukesh; Kumar, Mahesh

2018-04-20

Semiconductor quantum dots (QDs) have attracted tremendous attention owing to their novel electrical and optical properties due to the size dependent quantum confinement effects. This provides an advantage of tunable wavelength detection, which is essential to realize spectrally selective photodetectors. We report the fabrication and characterization of high performance narrow band ultraviolet photodetector (UV-B) based on In2O3 nanocrystals embedded in Al2O3 matrices. The In2O3 nanocrystals are synthesized in Al2O3 matrix by sequential implantation of In+ and N2+ ions and post-implantation annealing. The photodetector exhibits excellent optoelectronic performances with high spectral responsivity and external quantum efficiency. The spectral response showed a band-selective nature with a full width half maximum of ∼ 60 nm, and the responsivity reaches up to 70 A/W under 290 nm at 5 V bias. The corresponding rejection ratio to visible region was as high as 8400. The high performance of this photodetector makes it highly suitable for practical applications such as narrow-band spectrum-selective photodetectors. The device design based on ion-synthesized nanocrystals would provide a new approach for realizing a visible-blind photodetector. © 2018 IOP Publishing Ltd.

Predictive modeling, simulation, and optimization of laser processing techniques: UV nanosecond-pulsed laser micromachining of polymers and selective laser melting of powder metals

NASA Astrophysics Data System (ADS)

Criales Escobar, Luis Ernesto

One of the most frequently evolving areas of research is the utilization of lasers for micro-manufacturing and additive manufacturing purposes. The use of laser beam as a tool for manufacturing arises from the need for flexible and rapid manufacturing at a low-to-mid cost. Laser micro-machining provides an advantage over mechanical micro-machining due to the faster production times of large batch sizes and the high costs associated with specific tools. Laser based additive manufacturing enables processing of powder metals for direct and rapid fabrication of products. Therefore, laser processing can be viewed as a fast, flexible, and cost-effective approach compared to traditional manufacturing processes. Two types of laser processing techniques are studied: laser ablation of polymers for micro-channel fabrication and selective laser melting of metal powders. Initially, a feasibility study for laser-based micro-channel fabrication of poly(dimethylsiloxane) (PDMS) via experimentation is presented. In particular, the effectiveness of utilizing a nanosecond-pulsed laser as the energy source for laser ablation is studied. The results are analyzed statistically and a relationship between process parameters and micro-channel dimensions is established. Additionally, a process model is introduced for predicting channel depth. Model outputs are compared and analyzed to experimental results. The second part of this research focuses on a physics-based FEM approach for predicting the temperature profile and melt pool geometry in selective laser melting (SLM) of metal powders. Temperature profiles are calculated for a moving laser heat source to understand the temperature rise due to heating during SLM. Based on the predicted temperature distributions, melt pool geometry, i.e. the locations at which melting of the powder material occurs, is determined. Simulation results are compared against data obtained from experimental Inconel 625 test coupons fabricated at the National Institute for Standards & Technology via response surface methodology techniques. The main goal of this research is to develop a comprehensive predictive model with which the effect of powder material properties and laser process parameters on the built quality and integrity of SLM-produced parts can be better understood. By optimizing process parameters, SLM as an additive manufacturing technique is not only possible, but also practical and reproducible.

Characteristics of cholinoreceptors on identified TAN neurons of the ground snail Achatina fulica.

PubMed

Stepanov, I I; Losev, N A

2000-01-01

The characteristics of cholinoreceptors located on neurons TAN1, TAN2, and TAN3 of the ground snail Achatina fulica were studied by incubation of the central ganglia in a bath with cholinotropic preparations during intracellular recording of background neuron spike activity. Acetylcholine, nicotine, the selective n-cholinoreceptor agonist suberyldicholine, and the selective n-cholinoreceptor agonist 5-methylfurmethide concentration-dependently inhibited background spike activity to the level of complete blockade at concentrations of 500 microM. The m-cholinoblocker metamizil (500 microM) completely prevented the inhibitory activity of concentrations of 5-methylfurmethide of up to 500 microM. The central n-cholinoblocker etherophen (500 microM) completely blocked the inhibitory activity of 500 microM suberyldicholine. However, metamizil and etherophen added separately only partially decreased the inhibitory effects of acetylcholine but could not completely block the effect of acetylcholine. At the same time, mixtures of metamizil and etherophen (500 microM each) completely blocked the inhibition of background spike activity induced by acetylcholine. These results show that both classes of cholinoreceptors act on TAN neurons in the same direction.

Concentrate Supplement Modifies the Feeding Behavior of Simmental Cows Grazing in Two High Mountain Pastures.

PubMed

Romanzin, Alberto; Corazzin, Mirco; Piasentier, Edi; Bovolenta, Stefano

2018-05-16

During grazing on Alpine pastures, the use of concentrates in dairy cows' diet leads to a reduction of the environmental sustainability of farms, and influences the selective pressure on some plant species. In order to minimize the use of concentrates, it is imperative to obtain data on the grazing behavior of cows. The aim of this study was to assess the effect of concentrate levels on the behavior of dairy cows during grazing. One hundred and ten lactating Italian Simmental cows, that sequentially grazed two pastures characterized by Poion alpinae (Poion) and Seslerion caeruleae (Seslerion) alliance, were considered. For each pasture, eight cows were selected and assigned to two groups: High and Low, supplemented with 4 kg/head/d, and 1 kg/head/d of concentrate respectively. Cows were equipped with a noseband pressure sensor and a pedometer (RumiWatch system, ITIN-HOCH GmbH) to assess grazing, ruminating, and walking behavior. In addition, the plant selection of the animals was assessed. On Poion, increased supplement intake caused a more intense selection of legumes, without affecting feeding and walking times. On Seslerion, grazing time was higher in Low than High. Grazing management in alpine region must take into account the great variability of pastures that largely differ from a floristic and nutritional point of view.

A novel antagonist, phenylbenzene omega-phosphono-alpha-amino acid, for strychnine-sensitive glycine receptors in the rat spinal cord.

PubMed Central

Saitoh, T; Ishida, M; Maruyama, M; Shinozaki, H

1994-01-01

1. 3-[2'-Phosphonomethyl[1,1'-biphenyl]-3-yl]alanine (PMBA) is a novel glycine antagonist at strychnine-sensitive receptors. The chemical structure of PMBA, possessing both a glycine moiety and a phosphono group, is quite different from that of strychnine. 2. In the spinal motoneurone of newborn rats, glycine (100 microM-1 mM) induced depolarizing responses in a concentration-dependent manner. PMBA effectively inhibited depolarizing responses to glycine and other agonists, such as taurine and beta-alanine. The dose-response curves for glycine were shifted to the right in an almost parallel manner (pA2 value: 5.30 +/- 0.23, n = 5) by PMBA which was about 60 times less potent than strychnine (pA2 value: 7.08 +/- 0.21, n = 5) as a glycine antagonist. 3. PMBA (1-100 microM) did not interact with modulatory glycine sites on N-methyl-D-aspartate (NMDA) receptors, which suggests a high selectivity of PMBA for strychnine-sensitive glycine receptors. At considerably high concentrations (0.1 mM-1 mM), PMBA depressed responses to GABA (pA2 value: 3.57 +/- 0.24, n = 3). 4. PMBA inhibited the binding of [3H]-strychnine to synaptosomes from adult rat spinal cords; the IC50 values of PMBA, glycine and strychnine were 8 +/- 2, 9 +/- 3 and 0.08 +/- 0.04 microM, respectively (n = 5) for [3H]-strychnine (4.8 nM). 5. PMBA is a central excitant drug with relatively high potency and selectivity and should be useful as a pharmacological probe for analysing the mechanisms underlying physiological functions of glycine receptors. PMID:7812607

Support for distinct subcomponents of spatial working memory: a double dissociation between spatial-simultaneous and spatial-sequential performance in unilateral neglect.

PubMed

Wansard, Murielle; Bartolomeo, Paolo; Bastin, Christine; Segovia, Fermín; Gillet, Sophie; Duret, Christophe; Meulemans, Thierry

2015-01-01

Over the last decade, many studies have demonstrated that visuospatial working memory (VSWM) can be divided into separate subsystems dedicated to the retention of visual patterns and their serial order. Impaired VSWM has been suggested to exacerbate left visual neglect in right-brain-damaged individuals. The aim of this study was to investigate the segregation between spatial-sequential and spatial-simultaneous working memory in individuals with neglect. We demonstrated that patterns of results on these VSWM tasks can be dissociated. Spatial-simultaneous and sequential aspects of VSWM can be selectively impaired in unilateral neglect. Our results support the hypothesis of multiple VSWM subsystems, which should be taken into account to better understand neglect-related deficits.

CYP3A4 activity in four different animal species liver microsomes using 7-benzyloxyquinoline and HPLC/spectrofluorometric determination.

PubMed

Baririan, Narine; Desager, Jean-Pierre; Petit, Martine; Horsmans, Yves

2006-01-23

Some microplate-based direct assays with different fluorometric substrates have been developed, among which 7-benzyloxyquinoline (BOQ) has demonstrated the highest degree of selectivity for CYP3A subfamily. In our study, we firstly developed and validated an efficient, fast and cheap HPLC/spectrofluorometric analytical method to quantify 7-hydroxyquinoline (BOQ metabolite). Secondly, BOQ oxidation rate (1.95 +/- 0.24 microM/mg protein/min) was compared to that of midazolam (MDZ) (1.4 +/- 0.21 microM/mg protein/min), an other specific CYP3A probe. However, the difference did not reach statistically significance (test of Sign; p = 0.125, two tailed). Thirdly, the potential use of BOQ in other species than the rat (mouse, dog and monkey) was studied. The highest BOQ activity was observed in rat microsomes (3.75 micromol/mg protein/min) with lower P450 content (0.3 nmol/mg protein) compared to other species. Finally, the effect of CYP3A enzymes-selective inhibitor ketoconazole on the dealkylation of BOQ in control and dexamethasone (DM)-treated rat microsomes was studied. Ketoconazole inhibition potency was greater in control (IC(50) approximately 21.6 microM) compared to DM induced (IC(50) approximately 32.3 microM) microsomes. At concentrations greater than that considered to be enzyme-selective (e.g., 10-30 microM), ketoconazole inhibitory activity did not rise significantly, and at the maximal concentration tested (1,000 microM) a nearly similar inhibition (76%) was observed than that at 50 microM concentration (68.2%).

The effects of 595- and 1,064-nm lasers on rooster comb blood vessels using dual-wavelength and multipulse techniques.

PubMed

Li, Guang; Sun, Jianfang; Shao, Xuebao; Sang, Honggui; Zhou, Zhanchao

2011-10-01

After laser irradiation, hemoglobin can transform into methemoglobin and coagulum, which have high absorptivity of near-infrared light. Sequential irradiation with 595 nm and 1,064 nm may be more effective than single wavelength to decrease residual vessel number in rooster combs. Six protocols (single pulse with 595 nm, double pulse with 595 nm, single pulse with 1,064 nm, double pulse with 1,064 nm, sequential irradiation with 595 nm and 1,064 nm (multiplex), and a blank control group) were used to compare the effects of sequential and single-wavelength irradiation on reducing residual vessel number, as well as the epidermal side effects, in the rooster comb. Different treatment techniques were applied to the same comb, at the same time. The treated areas of the epidermis and the residual vessels were observed using an optical microscope. All five techniques were effective in decreasing the number of residual vessels in the comb, and the side effects on the epidermis were similar for all. Considering the selectivity of the 595-nm laser and the rich melanin in the human epidermis, the dual-wavelength laser has a distinct advantage in treating vascular lesions. The authors have indicated no significant interest with commercial supporters. © 2011 by the American Society for Dermatologic Surgery, Inc.

Development of an efficient genetic manipulation strategy for sequential gene disruption and expression of different heterologous GFP genes in Candida tropicalis.

PubMed

Zhang, Lihua; Chen, Xianzhong; Chen, Zhen; Wang, Zezheng; Jiang, Shan; Li, Li; Pötter, Markus; Shen, Wei; Fan, You

2016-11-01

The diploid yeast Candida tropicalis, which can utilize n-alkane as a carbon and energy source, is an attractive strain for both physiological studies and practical applications. However, it presents some characteristics, such as rare codon usage, difficulty in sequential gene disruption, and inefficiency in foreign gene expression, that hamper strain improvement through genetic engineering. In this work, we present a simple and effective method for sequential gene disruption in C. tropicalis based on the use of an auxotrophic mutant host defective in orotidine monophosphate decarboxylase (URA3). The disruption cassette, which consists of a functional yeast URA3 gene flanked by a 0.3 kb gene disruption auxiliary sequence (gda) direct repeat derived from downstream or upstream of the URA3 gene and of homologous arms of the target gene, was constructed and introduced into the yeast genome by integrative transformation. Stable integrants were isolated by selection for Ura + and identified by PCR and sequencing. The important feature of this construct, which makes it very attractive, is that recombination between the flanking direct gda repeats occurs at a high frequency (10 -8 ) during mitosis. After excision of the URA3 marker, only one copy of the gda sequence remains at the recombinant locus. Thus, the resulting ura3 strain can be used again to disrupt a second allelic gene in a similar manner. In addition to this effective sequential gene disruption method, a codon-optimized green fluorescent protein-encoding gene (GFP) was functionally expressed in C. tropicalis. Thus, we propose a simple and reliable method to improve C. tropicalis by genetic manipulation.

Presynaptic mGlu1 and mGlu5 autoreceptors facilitate glutamate exocytosis from mouse cortical nerve endings.

PubMed

Musante, Veronica; Neri, Elisa; Feligioni, Marco; Puliti, Aldamaria; Pedrazzi, Marco; Conti, Valerio; Usai, Cesare; Diaspro, Alberto; Ravazzolo, Roberto; Henley, Jeremy M; Battaglia, Giuseppe; Pittaluga, Anna

2008-09-01

The effects of mGlu1 and mGlu5 receptor activation on the depolarization-evoked release of [3H]d-aspartate ([3H]D-ASP) from mouse cortical synaptosomes were investigated. The mGlu1/5 receptor agonist 3,5-DHPG (0.1-100microM) potentiated the K+(12mM)-evoked [3H]D-ASP overflow. The potentiation occurred in a concentration-dependent manner showing a biphasic pattern. The agonist potentiated [3H]D-ASP exocytosis when applied at 0.3microM; the efficacy of 3,5-DHPG then rapidly declined and reappeared at 30-100microM. The fall of efficacy of agonist at intermediate concentration may be consistent with 3,5-DHPG-induced receptor desensitization. Facilitation of [3H]D-ASP exocytosis caused by 0.3microM 3,5-DHPG was prevented by the selective mGlu5 receptor antagonist MPEP, but was insensitive to the selective mGlu1 receptor antagonist CPCCOEt. In contrast, CPCCOEt prevented the potentiation by 50microM 3,5-DHPG, while MPEP had minimal effect. Unexpectedly, LY 367385 antagonized both the 3,5-DHPG-induced effects. A total of 0.3microM 3,5-DHPG failed to facilitate the K+-evoked [3H]D-ASP overflow from mGlu5 receptor knockout (mGlu5-/-) cortical synaptosomes, but not from nerve terminals prepared from the cortex of animals lacking the mGlu1 receptors, the crv4/crv4 mice. On the contrary, 50microM 3,5-DHPG failed to affect the [3H]D-ASP exocytosis from cortical synaptosomes obtained from crv4/crv4 and mGlu5-/-mice. Western blot analyses in subsynaptic fractions support the existence of both mGlu1 and mGlu5 autoreceptors located presynaptically, while immunocytochemistry revealed their presence at glutamatergic terminals. We propose that mGlu1 and mGlu5 autoreceptors exist on mouse glutamatergic cortical terminals; mGlu5 receptors may represent the "high affinity" binding sites for 3,5-DHPG, while mGlu1 autoreceptors represent the "low affinity" binding sites.

Sequential Extraction Results in Improved Proteome Profiling of Medicinal Plant Pinellia ternata Tubers, Which Contain Large Amounts of High-Abundance Proteins

PubMed Central

An, SuFang; Gong, FangPing; Wang, Wei

2012-01-01

Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs), mainly mannose-binding lectin (agglutinin), exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE). Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa) and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae. PMID:23185632

Sequential extraction results in improved proteome profiling of medicinal plant Pinellia ternata tubers, which contain large amounts of high-abundance proteins.

PubMed

Wu, Xiaolin; Xiong, Erhui; An, Sufang; Gong, Fangping; Wang, Wei

2012-01-01

Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs), mainly mannose-binding lectin (agglutinin), exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE). Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa) and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae.

Expanding Lipidome Coverage Using LC-MS/MS Data-Dependent Acquisition with Automated Exclusion List Generation

NASA Astrophysics Data System (ADS)

Koelmel, Jeremy P.; Kroeger, Nicholas M.; Gill, Emily L.; Ulmer, Candice Z.; Bowden, John A.; Patterson, Rainey E.; Yost, Richard A.; Garrett, Timothy J.

2017-05-01

Untargeted omics analyses aim to comprehensively characterize biomolecules within a biological system. Changes in the presence or quantity of these biomolecules can indicate important biological perturbations, such as those caused by disease. With current technological advancements, the entire genome can now be sequenced; however, in the burgeoning fields of lipidomics, only a subset of lipids can be identified. The recent emergence of high resolution tandem mass spectrometry (HR-MS/MS), in combination with ultra-high performance liquid chromatography, has resulted in an increased coverage of the lipidome. Nevertheless, identifications from MS/MS are generally limited by the number of precursors that can be selected for fragmentation during chromatographic elution. Therefore, we developed the software IE-Omics to automate iterative exclusion (IE), where selected precursors using data-dependent topN analyses are excluded in sequential injections. In each sequential injection, unique precursors are fragmented until HR-MS/MS spectra of all ions above a user-defined intensity threshold are acquired. IE-Omics was applied to lipidomic analyses in Red Cross plasma and substantia nigra tissue. Coverage of the lipidome was drastically improved using IE. When applying IE-Omics to Red Cross plasma and substantia nigra lipid extracts in positive ion mode, 69% and 40% more molecular identifications were obtained, respectively. In addition, applying IE-Omics to a lipidomics workflow increased the coverage of trace species, including odd-chained and short-chained diacylglycerides and oxidized lipid species. By increasing the coverage of the lipidome, applying IE to a lipidomics workflow increases the probability of finding biomarkers and provides additional information for determining etiology of disease.

EDITORIAL: The Fifth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2005)

NASA Astrophysics Data System (ADS)

Suzuki, Yuji

2006-09-01

This special issue of Journal of Micromechanics and Microengineering contains a selection of papers from the Fifth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2005). The meeting was held on 28-30 November 2005 in Tokyo, Japan, and was supported by the 21COE Program 'Mechanical Systems Innovation' at the University of Tokyo. Power MEMS is one of the newest categories of MEMS, encompassing microdevices and microsystems for power generation, energy conversion and propulsion. The series of PowerMEMS workshops started in 2000 in Sendai, Japan and then moved to Tsukuba, Makuhari, Kyoto and Tokyo. At the 2005 meeting there were four invited, 25 oral and 26 poster presentations from 14 different countries. From the 55 papers in the proceedings, 18 papers have been selected for this special issue. The papers were chosen on the basis of their quality, scientific impact and relevance to the scope of the journal. The authors of the selected papers were invited to expand their manuscripts beyond the workshop page limitation and to revise the papers to meet the criteria of archival journal publication. All papers have been subjected to the journal's standard peer review process. The papers included herein are ordered according to four areas: energy harvesting, micro combustors and fuel processors, micro fuel cells, and micro engines and generators. It is my pleasure to present these selected papers from PowerMEMS 2005, and I hope that this special issue provides a valuable overview of the latest research in micro and nanotechnology for power generation and energy conversion.

MaMiCo: Software design for parallel molecular-continuum flow simulations

NASA Astrophysics Data System (ADS)

Neumann, Philipp; Flohr, Hanno; Arora, Rahul; Jarmatz, Piet; Tchipev, Nikola; Bungartz, Hans-Joachim

2016-03-01

The macro-micro-coupling tool (MaMiCo) was developed to ease the development of and modularize molecular-continuum simulations, retaining sequential and parallel performance. We demonstrate the functionality and performance of MaMiCo by coupling the spatially adaptive Lattice Boltzmann framework waLBerla with four molecular dynamics (MD) codes: the light-weight Lennard-Jones-based implementation SimpleMD, the node-level optimized software ls1 mardyn, and the community codes ESPResSo and LAMMPS. We detail interface implementations to connect each solver with MaMiCo. The coupling for each waLBerla-MD setup is validated in three-dimensional channel flow simulations which are solved by means of a state-based coupling method. We provide sequential and strong scaling measurements for the four molecular-continuum simulations. The overhead of MaMiCo is found to come at 10%-20% of the total (MD) runtime. The measurements further show that scalability of the hybrid simulations is reached on up to 500 Intel SandyBridge, and more than 1000 AMD Bulldozer compute cores.

The collection of MicroED data for macromolecular crystallography.

PubMed

Shi, Dan; Nannenga, Brent L; de la Cruz, M Jason; Liu, Jinyang; Sawtelle, Steven; Calero, Guillermo; Reyes, Francis E; Hattne, Johan; Gonen, Tamir

2016-05-01

The formation of large, well-ordered crystals for crystallographic experiments remains a crucial bottleneck to the structural understanding of many important biological systems. To help alleviate this problem in crystallography, we have developed the MicroED method for the collection of electron diffraction data from 3D microcrystals and nanocrystals of radiation-sensitive biological material. In this approach, liquid solutions containing protein microcrystals are deposited on carbon-coated electron microscopy grids and are vitrified by plunging them into liquid ethane. MicroED data are collected for each selected crystal using cryo-electron microscopy, in which the crystal is diffracted using very few electrons as the stage is continuously rotated. This protocol gives advice on how to identify microcrystals by light microscopy or by negative-stain electron microscopy in samples obtained from standard protein crystallization experiments. The protocol also includes information about custom-designed equipment for controlling crystal rotation and software for recording experimental parameters in diffraction image metadata. Identifying microcrystals, preparing samples and setting up the microscope for diffraction data collection take approximately half an hour for each step. Screening microcrystals for quality diffraction takes roughly an hour, and the collection of a single data set is ∼10 min in duration. Complete data sets and resulting high-resolution structures can be obtained from a single crystal or by merging data from multiple crystals.

Mining of high utility-probability sequential patterns from uncertain databases

PubMed Central

Zhang, Binbin; Fournier-Viger, Philippe; Li, Ting

2017-01-01

High-utility sequential pattern mining (HUSPM) has become an important issue in the field of data mining. Several HUSPM algorithms have been designed to mine high-utility sequential patterns (HUPSPs). They have been applied in several real-life situations such as for consumer behavior analysis and event detection in sensor networks. Nonetheless, most studies on HUSPM have focused on mining HUPSPs in precise data. But in real-life, uncertainty is an important factor as data is collected using various types of sensors that are more or less accurate. Hence, data collected in a real-life database can be annotated with existing probabilities. This paper presents a novel pattern mining framework called high utility-probability sequential pattern mining (HUPSPM) for mining high utility-probability sequential patterns (HUPSPs) in uncertain sequence databases. A baseline algorithm with three optional pruning strategies is presented to mine HUPSPs. Moroever, to speed up the mining process, a projection mechanism is designed to create a database projection for each processed sequence, which is smaller than the original database. Thus, the number of unpromising candidates can be greatly reduced, as well as the execution time for mining HUPSPs. Substantial experiments both on real-life and synthetic datasets show that the designed algorithm performs well in terms of runtime, number of candidates, memory usage, and scalability for different minimum utility and minimum probability thresholds. PMID:28742847

Intermixing of InP-based quantum dots and application to micro-ring resonator wavelength-selective filter for photonic integrated devices

NASA Astrophysics Data System (ADS)

Matsumoto, Atsushi; Matsushita, Asuka; Takei, Yuki; Akahane, Kouichi; Matsushima, Yuichi; Ishikawa, Hiroshi; Utaka, Katsuyuki

2014-09-01

In this study, we investigated quantum dot intermixing (QDI) for InAs/InGaAlAs highly stacked QDs on an InP(311)B substrate with low-temperature annealing at 650 °C in order to realize integrated photonic devices with QDs and passive waveguides. In particular, we adopted the method of introducing point defects by ICP-RIE to realize a blue shift of the PL peak wavelength by about 150 nm. Moreover, we successfully fabricated double micro-ring resonators by QDI. The output power contrasts of the devices were found to be 9.0 and 8.6 dB for TE and TM modes, respectively.

The selectable hyperspectral airborne remote sensing kit (SHARK) as an enabler for precision agriculture

NASA Astrophysics Data System (ADS)

Holasek, Rick; Nakanishi, Keith; Ziph-Schatzberg, Leah; Santman, Jeff; Woodman, Patrick; Zacaroli, Richard; Wiggins, Richard

2017-04-01

Hyperspectral imaging (HSI) has been used for over two decades in laboratory research, academic, environmental and defense applications. In more recent time, HSI has started to be adopted for commercial applications in machine vision, conservation, resource exploration, and precision agriculture, to name just a few of the economically viable uses for the technology. Corning Incorporated (Corning) has been developing and manufacturing HSI sensors, sensor systems, and sensor optical engines, as well as HSI sensor components such as gratings and slits for over a decade and a half. This depth of experience and technological breadth has allowed Corning to design and develop unique HSI spectrometers with an unprecedented combination of high performance, low cost and low Size, Weight, and Power (SWaP). These sensors and sensor systems are offered with wavelength coverage ranges from the visible to the Long Wave Infrared (LWIR). The extremely low SWaP of Corning's HSI sensors and sensor systems enables their deployment using limited payload platforms such as small unmanned aerial vehicles (UAVs). This paper discusses use of the Corning patented monolithic design Offner spectrometer, the microHSI™, to build a highly compact 400-1000 nm HSI sensor in combination with a small Inertial Navigation System (INS) and micro-computer to make a complete turn-key airborne remote sensing payload. This Selectable Hyperspectral Airborne Remote sensing Kit (SHARK) has industry leading SWaP (1.5 lbs) at a disruptively low price due, in large part, to Corning's ability to manufacture the monolithic spectrometer out of polymers (i.e. plastic) and therefore reduce manufacturing costs considerably. The other factor in lowering costs is Corning's well established in house manufacturing capability in optical components and sensors that further enable cost-effective fabrication. The competitive SWaP and low cost of the microHSI™ sensor is approaching, and in some cases less than the price point of Multi Spectral Imaging (MSI) sensors. Specific designs of the Corning microHSI™ SHARK visNIR turn-key system are presented along with salient performance characteristics. Initial focus market areas include precision agriculture and historic and recent microHSI™ SHARK prototype test results are presented.